> What is reach front end? The one where you wait your js to arrive only for it to issue own API calls, then wait data to arrive, then it to be parsed and finaly shown?

No, that's your own straw man definition.

> It would not surprise my if some dumb turbolinks staff would beat a lot of fancy frameworks performance an UX wise.

Turbolinks absolutely does not beat a well written SPA UX-wise.