Yep almost every (serious) TS dev only uses --noEmit for development by default because they use VSCode/IDEs as their typechecking engines and then have something like esbuild for delivering the content to the browser locally. I've never had performance issues with either step and I use both daily.

The raw output speeds aren't a very good 'practical real world example' as the OP described it.

If anything in dev ESLint (+ Copilot) is the slow ones that I sometimes noticed, but there is already Rust driven replacements maturing in the pipeline as we speak.