I don't think we can blame the web for software bloat, that was happening before the web. Software expands to take the available resources! Also the hard part here isn't designing an elegant system, anyone with good taste can do that! The hard part is the business problem of gaining adoption.

That is why I like web assembly, a browser is really a hypervisor - it makes distributing applications relatively safe (compared to downloading exe files!)
we can build another layer with webassembly, and then remove the old layer (html etc)

If you wanna start completely from scratch... maybe try urbit or ceptr (urbit, but by nice people)

I think these projects trip them selves up by trying to reinvent everything they end up stuck down every rabbit hole...