Do you know how difficult it is to tell someone your email address with your custom domain name? It seems people only know the big players: @gmail.com, @outlook.com or @gmx.de and @web.de in Germany. But telling someone to mail to @jlelse.de, @jlelse.dev (or any of my other domain names) is a bit more difficult, I always need to spell letter for letter and that is really annoying. But this has now come to an end.
I already wrote about that you should think about paying for your email service (or host it yourself if you’re crazy), but another important aspect is the email address itself. Many people (and I also did this in the past) use an email address given by their provider like an address with @gmail.com, @outlook.com or any other. Using such an address is free of course, but it is definitely some kind of lock-in.