I hope I don't have to explain why Google is bad, but just to give a few reasons to switch to alternatives: You'll probably get better privacy because those alternatives collect less data about you, your data won't get sold to advertisers or government organizations that easily and you help to prevent a monopoly. Sometimes alternatives are also just better than the Google product and don't lock you in so much.
Here is my list of Google alternatives I use or can recommend. Sure, some of those alternatives cost money, but I think only if you pay for a service, you can really trust it. There are also no referral or tracking links, everything I list here, I list just because I'm convinced of it!
Google Search: I use Startpage (update: read about changes at StartPage here - I use Searx now), it's like an anonymizing proxy to Google. DuckDuckGo (uses Bing from Microsoft in the backend) or Qwant (uses it's own index) have good privacy too, but I find that Startpage's results are the best among those. Although Startpage uses Google in the backend, Google can't see which request is coming from which person and Startpage doesn't track you and only shows non-personalized ads but they are profitable though. I prefer Startpage over DuckDuckGo, because they are a European company instead of a US-based one.
Google Maps: I use Here WeGo whenever I need to find routes or need navigation. It also has great support for offline maps and even shows speed limits, something Google Maps isn't doing. When you just need maps, OpenStreetMap or Qwant Maps (which is using OSM too) are good options too.
Gmail: I really hate Gmail and definitely urge you to find an alternative. Because so many people are using Gmail, Google thinks they can do whatever they want. Although email should be decentralized, they reject perfectly fine emails from perfectly fine mail servers or put them to the spam folder. I recommend getting your own domain (to be able to switch to another provider more easily). I use my own mailserver with mailcow (it's quite easy to setup) or recommend the hosted version of mailcow or FastMail, which I used previously. On the desktop I use Thunderbird to read mails, on my phone I use K9-Mail.
Chrome: Browsers are a hot topic. Google has reached almost browser monopoly with it's own browser Chrome and it's underlying engine Chromium. Most of the browser alternatives like Brave, Opera or Vivaldi are using Chromium. If everyone is using the same browser engine and that is controlled by Google, they can do evil things like removing APIs needed by ad blockers to secure their own business. And it also has the effect that websites are just getting optimized for Chromium and other browsers are ignored. A browser monoculture is no good thing (remember Internet Explorer). I use Firefox with telemetry turned off and the uBlockOrigin plugin installed. It also feels much faster than the Chromium-based Vivaldi I use on my work laptop. I don't recommend Brave.
Google Drive and Google Photos: Google Drive might be a nice service, you get a few gigabytes of online storage for free. Google Photos even backups all your photos for free. But do you know what happens with all that data? Only Google knows. I run an instance of NextCloud on a tiny computer at home, but I can also recommend the German hosting provider Hetzner with their NextCloud offers. NextCloud gives you the ability to sync files between all your computers or just store them in the cloud. With the Android app you can also setup automatic photo upload, so your photos are safe. But you can be sure that no algorithms scan your private pictures.
Google Calendar and Google Contacts: If you use an alternative mail service or NextCloud, you can actually choose where to put your calendars and contacts instead. Most mail providers provide support for them and also NextCloud has apps to store calendars and contacts. On your Android phone you can sync them via CalDav and CardDav using DAVx⁵ and use the Calendar and Contacts apps by Simple Mobile Tools to access them.
Android and Google Play: If you have an Android device, that device probably has a lot of Google apps and services running. If you're device is supported, you can try flashing LineageOS and use F-Droid (be aware - their server is sometimes really slow) to get free / libre and open source (F/LOSS) apps. Or if one app is only available on Google Play, you can use the Aurora Store to download it (you can also use F-Droid and Aurora without LineageOS). I must admit that this is a topic where I need to get more strict and actually use Google Play less.
YouTube: YouTube is a great source for every kind of videos, whether for entertainment or educational purposes, you can find a lot of things on YouTube. Sadly there isn't any mainstream alternative yet and a lot of videos are only available on YouTube but not on open, free and distributed platforms like PeerTube. However you can reduce the tracking of YouTube by using the NewPipe app on your phone or Invidious in the browser. You can also subscribe to YouTube channels via RSS (Google link!) and watch videos using your news reader. (That could also help watching less YouTube, because you see no recommended videos.)
Google Password Manager: Nowadays the normal internet user has dozens of accounts on many internet services. Without writing them down you can't remember all those different passwords, when you follow the good practice of using a separate secure password (probably auto-generated) for every service. I use Bitwarden to use safe and long passwords (which I would never be able to remember) for every service. In Bitwarden I have saved over 200 logins (do I have too many accounts? - a lot of those passwords are for self-hosted services though). I even self-host the Rust-implementation of the Bitwarden server, but the normal free or premium plans from Bitwarden are perfectly fine too, although I would recommend buying premium, because that also gives you support for 2FA and supports the developer behind Bitwarden.
Google News: I mentioned news readers. RSS is still alive and subscribing to a few news sites using RSS is way better than letting Google curate news for you. I use Miniflux, which also has a hosted version for just a few bucks per year.
Google Translate: My choice of translation service is DeepL. It's a German company and also provides the site Linguee. And the translations are often far better than what Google Translate does. Sadly they have no official mobile app yet.
Google Analytics: Back in the days I used Google Analytics too, but since GDPR got into effect and I realized I didn't really get any benefit from those analytics, I decided to stop using Google Analytics and use something more privacy friendly instead. First I chose Fathom, but nowadays I'm using my own solution KISSS instead to count views on my websites. All the information it collects are the time of the page view, the URL, the referrer domain and the browser name and version. I think that's enough.
Google Domains and Google Cloud: If you plan to get your own domain for your emails or even want to host a website or self-host one of the mentioned services, using Google Domains isn't the best choice. In this case it's less about the privacy, but more about prices. I often use Porkbun oder INWX to register domains. But it's worth to take a look at TLD List before chosing a provider to see which one has the best prices. My hosting provider of choice is Hetzner which has servers in Germany and Finland and has great prices for Virtual Private Servers (VPS). Much cheaper than Digital Ocean or Linode too.
If you are interested into more alternatives, also for other huge American corporations, you can take a look at switching.software.