He can buy one of those other competitors used by right-wing folks. Hell, if "free speech" is so important to him and to everyone else he wants to rescue he can just tweet to use those other platforms. It's certainly cheaper.
Spoiler alert: other platforms are not in any way more "free speech". Gab for example bans porn, which is both free speech protected by the First Amendment, and allowed on Twitter. TRUTH Social seems to forbid a lot of things, such as depictions of violence, lewd content, libelous/slanderous content and lying (true to their name, I guess?).
Twitter is "losing hundreds of millions of dollars every year" (I don't know if that's how we're using air quotes now, just following your lead), it is already circling the drain. No need to buy anything, it would be trivial for him to setup a clone and fund it indefinitely while it tears itself apart.
Twitter is where the network effect and users are, so no it makes more sense to take over Twitter and shape it to your own views if you are a billionaire who wants to make an impact on public discourse and free speech.
