I stumbled on to /e/ some time ago (when it was announced and when they announced pre-installed refurbished phones with /e/), but took another look today after the launch of Android 10. In my opinion Android's development is very worrying as it get's more coupled to Google with every release. I don't like iOS either, because its a completely walled garden.
/e/ tries to provide help to completely break free from Google by not only offering an alternative smartphone OS, but also alternative hosted services like email, cloud storage etc.
Although, I wish there would be a viable alternative to the Android and iOS doupoly, Linux phone's aren't ready yet and even with the Librem 5 and Pine Phone. Until then, the only alternative I see is using an un-googled Android.
In the past I've used phones with LineageOS, but back then my reason was that the phones didn't get any more updates but Lineage offered a newer Android version. Now I look at LineageOS or the Lineage-based /e/ to escape Google's tracking or even the manufacturers tracking (Xiaomi for example is trying to sell phones very cheaply, but generate income with ads on the phones).
The problem is that flashing unofficial software on a new phone can make things with warranty a lot more difficult and in the past I had to make use of warranties with phones already. It also seems that the custom ROM community is much less active nowadays than it used to be. It always takes a long time until a phone get's supported by some ROMs, if it get's support at all.