Well, of course. But TSC output (transpiled JS source code) is then run by a JS runtime like Node that has a VM like V8 that makes an internal representation for the JS code. Using Bun or Deno allows you to go to a VM IR from the TypeScript directly without a need for TSC transpilation into JS first.

But as @keturakis pointed out (thanks!), Deno/Bun still rely on TSC, which I was not aware of.