Then do what Gab, Gettr and Truth Social did and 'build your own platform'. If not that, then use a Mastodon instance like mastodon.social as an alternative?
The only thing these networks censor is anything that is illegal in their hosted jurisdiction i.e the US.
The fediverse (network of activitypub servers, including mastodon) itself doesn't censor anything at all, but if you don't moderate your instance then other instances might decide to stop federating with you to protect their users.
As far as I understood, they're not doing that on a case-by-case basis, but are using centralized block-lists (which every admin can choose to follow automatically). That's a step up from raw centralized censorship, but it's not a big step.
Most admins AFAIK don't have centralized blocklists but when the new bad instances pop up there tend to be #fediblock posts pretty fast, and they get shared pretty widely.
The only thing these networks censor is anything that is illegal in their hosted jurisdiction
Truth Social has apparently banned (and shadow banned) lots of people for posting anti-Trump and anti-GOP political messages.
Probably similar to what is currently happening on all the other platforms censoring dissent.
What do you mean? Be a billionaire and buy the platform?
You don't actually need to be a billionaire to have a platform. Those who felt censored just created their own social media. Some prominent figures in extreme right community are blue collar workers.
What's the plan to do that when they censor all dissent on the platforms they just bought?