instead of the “Mastodon appraoch” we take the “Replit approach”
I'm confused by the continual references to the Replit. Once you have Replit-style power, you can do Mastodon interop—but it keeps you dependent on third-party SaaS. Continuing to violate the principle of least power isn't really any improvement. If you're going to shoot for displacing the status quo, it should be to enable public participation from people who have nothing more than a Neocities account or a static site published with GitHub Pages or one of the many other providers. Once you bring "live" backends into this (in contrast to "dead" media like RSS/Atom), you've pretty much compromised the whole thing.