The thing is that these places only have value if people put in an effort, which is more likely to be the case when the platform and/or technology is new and only known by people who a priori have put in an effort to access it at all. When you mostly accessed web sites from desktop computers, you would be limited to use online platforms in the relatively small time window where you had free time at home, so the personal cost of using the platform was higher because you had to choose to take that time from other tasks that also required your computer.

Now everyone have a smartphone in their pockets and can access any online service at any time of the day, so the required effort to use them is a small fraction of what it used to be. As a result, the average user is not motivated to actually put in any effort, and because of this the quality suffers tremendously.

Maybe we should raise that lower bound on effort by requiring users to solve CAPTPTYCs - Completely Automated Programs To Prove That You Care - before you were allowed to interact with anyone online. A sort of proof-of-work for people to ensure that they have spent at least as much time on the content as they have on solving the puzzle that allowed them to publicize it.