People don't really care about anything other than convenience. Twitter could be grinding up puppies live on camera and most people would just shrug and be like "well the good memes are here".

Personally I think that's downstream from how we're all too polite about shit like this. We just smile and change the topic instead of doing the intensely uncomfortable "You really shouldn't use twitter" conversation. But also we're all too... childish, I guess, because most people if someone says that will not respond with "You make a good point and I will change in accordance," but rather with "Fuck you for saying things that make me feel bad. You suck. I'm not listening to anything you say."

So I guess we're fucked because people are immature, fragile, little shits.

if the problem is that major platforms are centralized, opaque, and controlled by corporations, why would the solution be yet another centralized platform controlled by a corporation?

Because people are brainwashed into only trusting billionaires, corporations, brand names, and consumer packaged goods to solve all our problems.

A classical sign of an early worldcentric worldview that is more about competition than about collaboration. A level "orange" in Integral theory. But humankind is continuing its development to late worldcentric worldview "green" level and more. And Fediverse is helping with that!

Alternatives are great if only people were using them.

The problem is building the network. Nobody uses it because nobody uses it and nobody will use it until everybody uses it.

That has always been and will always be the primary problem. You can solve all of the other problems and it won't matter.