Has anyone found a good internet provider for apartments that are pre-wired with AT&T?

I'm about to move apartments so will have to set up internet again, and I was wondering if anyone has found a better solution/provider that has good, cheap internet, especially in apartments that are "pre-wired" for AT&T (I don't fully understand what that means, assuming it just means I have to get AT&T wifi through some provider).

In my current place, the wifi refuses to work on my phone after 10pm for more than a few minutes at a time, and the wifi is frequently low or drops during the day too.

Verizon or cricket whatever that say they're $15/month (I'm paying nearly $90 right now, with the modem rental), but I'm not even sure if I can use them.

I don't even know how the pre-wiring works, whether changing the provider is just who you're paying to give you AT&T's wifi (sort of similar to my understanding of how electricity providers work), so maybe this is a pointless question.

Any recommendations?