> Getting rid of npm and doing things manually won't make building SPAs have fewer dependencies, build would be incredibly slow and painful.

Honestly, I don't think this is true in the slightest. Rather, I hypothesize that people want to use such tooling and think the alternatives are slower, which I don't think is true.

If people actually did use fewer dependencies, people would have actually have websites that didn't take ages to load and were responsive.

So the existing ecosystems are just bad.