The Play store and what it gives you is incredibly hard to live without, unless you really just want to use your phone for texting, browsing, and calling. If you're a minimalist, then great. If you're accustomed to what a smartphone can do, not so great.
The alternative app stores are full of unimpressive, small scale apps. Dozens of calculators and little games, but no maps apps (of worth), no yelps, no IMDb (which I use often), no Sheets or Photos, the list is huge. I'm sorry but these apps make a smartphone worthwhile.
To avoid such a spartan experience, I ended up just installing microG (an open source replacement for Google's Play Services) and Aurora (a replacement Play store client, which allows me to install most apps from the Play store).
The problem is that most modern apps require a mammoth cloud backend, which costs big money to run, which means you're going to need a huge company running it. You'll never find big scale apps like this on F-droid.