People use them out of desperation/necessity, not because they work at actually helping you find a partner or whatever it is you're looking. They work at keeping you hooked on the platform, hoping in vain you'll eventually find someone if you stick there long enough.

To quote someone else: There's this old man playing a crooked game every day and loosing his money so a youngster approaches him saying "don't you know this game is crooked old man, why are you still playing it?", to which the old man replies "I know it's crooked, but it's the only game in town".

The crooked game is the dating apps. For many people, it's the only option of dating and meeting new people outside their social circles, which is why they're used even if most people hate them, not because they're good.