Things like Reddit and Twitter are bad for billionaires. It makes it harder for them to exploit you when there is a public place to talk about their bullshit.
That was my reaction when Elon first bought twitter. It's like he's so stupid he thinks Twitter is the only possible platform that could ever be a twitter.
It turns out, we're all pretty clever at figuring out places to talk. The talking is going to happen. Where we do the talking keeps changing.
He never actually wanted to buy Twitter. He was just running his mouth to manipulate the market.
Twitter called his bluff and took him to court. He tried to weasel out of it with various excuses (like there are too many bots) but it didn't work. When he came close to having the court accessing his personal communications, he folded and bought Twitter.
He massively overpaid for it compared to the already inflated market price, instantly losing many billions. Must have had some insanely illegal dirt in those communications for it to be worth it.
So no, it wasn't some machiavellian plan to disrupt public communications. Musk is just not a very smart greedy asshole.