[1]: https://www.extremetech.com/mobile/235594-yes-google-play-is...
That's why you need one of the libraries that attempts to replace the google services.
Mozilla lets anyone download addons from anywhere, likewise I should be able to download an apk to my desktop and install on my phone.
Without the Play store, I had to take long hard look at what apps are really essential to me, for which I cannot find a FOSS alternative. Turns out, except Spotify and banking, there was none! Without Google Play, I did not really feel the need to fill my phone with various apps... My primary email and SMS was all the communication I needed.
In the beginning, I missed my notifications. I felt almost uneasy if I did not check my phone every 30 minutes because I felt like I could be missing some urgent notification. However, after only a week, I noticed that nothing of importance was lost, but more importantly, how much focus I reclaimed!
I know this sounds cheesy, but de-cluttering my phone made me realize how much all the apps strived for my attention all the time.