I chatted with an IM startup earlier this year who had strong relationships with creators who had large audiences, in the millions. The creators were on other platforms and they were flirting with joining this startup. From the perspective of these creators, their major frustration centered around (1) that they were bound to the sometimes bizarre and constantly-changing terms of the platform [can't say this or strike for that] and (2) they were heavily restricted by the fee's on the platform when it came to monetization.

Your idea for "a user-fare ecosystem of true free but non-harmful speech" could strike two birds with one stone here. If your system is somewhat decentralized [we can't take that down because we just don't host it] with an open and transparent means of payment where you monetize from the boosts and not torturing creators with unreasonable fee's , then I think you could be onto something. Luring a couple of the big creators onto your platform may start the snowball effect you'd need to overcome the strong moat twitter already enjoys and many have failed to overcome.