If last time you tried @fdroidorg, it looked outdated and was difficult to use, now might be a good moment to give it another go.

The upcoming 2.0 (in alpha release) UI is modern and easy-to-use.

More users non-Google Android apps have, the better future Android will have as a whole.

Support app creators who won't go after your data or cluter everything with predatory in-app-purchase strategies.

Even if you don't care about Open Source, embracing devs here makes your phone better.