I'm a sceptic to the claims; most build speedups I've seen come from the bypass of Typescript type checking/compiler errors. Since there is no other competetive compiler to Typescript than the official (and slow) tsc, I think vite works this way too? Getting hot reload and fast page refreshes is nice, but the idea is that if I get a compiler error, I ought to fix it first before I move to the browser to test my code.