AlternativeTo is a site I use quite a bit. Personally I use it when I get fed up with an Android app having too many ads / creepy network behavior or want to find a self-hostable version of a freemium service.
It has filters for free, open source, platform type, etc. From my understanding it’s all crowd sourced, so if you disagree with a rating put in a vote! Sharing this in hopes that others find it as useful as I do.
If you know of similar or better resources I would love to hear about them.
Edit: many people are noting that the comments and reviews are out of date. I agree! Despite that I still find it to he useful. It would be great if this little bit of visibility gets more folks engaged over there to improve it.
It’s mostly that it’s just an older site and the voting/review system goes back by over a decade. Much of the information you’re gonna get on there is just dated, pure and simple, and that reflects in the rankings.
And as you said, the categories aren’t curated well enough. Too many unrelated suggestions.