I listed frameworks that makes majority of the market share that are based on JSX and react-like reconciliation loop. This architecture is also now dominate in the mobile apps space via React Native and Flutter as well.
So I am not sure what you're talking about. The industry has largely stabilised on this architecture because it works. So I don't know who this "we" you're talking about or what you're even talking about anymore.
I have no idea if that's accurate, but let's assume for a moment that it is.
- Vue supports JSX, but it is not the default.
- Angular does not support JSX.
- Svelte, which you neglected to mention, does not support JSX.
- Solid does indeed use JSX, as of course does React.
So two out of the five main SPA frameworks don't even support JSX, and another doesn't typically use it.
As I said, you may have stabilised on JSX, "we" have not.