Twitter is also not a "public forum". They are a private company (exactly like Tesla) and can choose what people and what content they want to serve.
If what you have to say is so revolutionary, surely people will be coming to your new site in droves to hear your amazing commentary they can't get on Twitter.
Except nobody actually cares about what these people have to say, or else they'd have already done so. Half the time you can bet it's some middle aged dude pissed off that he got reported for calling someone a slur or spreading 5G-mind-control-level conspiracy theories.