I never understood it myself, was never active on anything but IRC. But ActivityPub seems truly magic when it comes to promoting communication across boundaries such as corporations and software stacks, so I jumped on it back in 2017 and loved seeing it blow up in 2022.
There are clearly a lot of very nice, and very normal, people on there who just love the concept of microblogging. Who am I, or you, to stand in their way? And why should they depend on one corporation to communicate when they can take it into their own hands?
It's really a very natural progression, just like we have many ISPs, phone companies, or anything else in society.
Because many are not nice and the platforms clearly have been abused, drive division in society and are bad for mental health. That's why we can't have nice things.
But at the same time I just learned of a protest here in my town, via social media. So it's also helping people organize IRL.
If you see disinformation and find yourself in an echo chamber on a platform where you can chose who you see and engage with, I am afraid it's not the platform's fault.