React is not only 5.3kb because that’s not the only piece you will need to actually use it. Check out the bundle of CRA for a real-world example.

I agree with the general sentiment though. I think the issue is that it’s easy to just import the whole npm registry in a bundle and ship it — and it’s too hard to trim it down.

For you a 2MB bundle is ok, but for me it’s taking 30 seconds to open this site and I’m standing here. That’s not ok.

Frameworks like Next.js provide a sane base for this; Most others don’t.