I like where the Rails team is going with Rails. No JS bloat at all, just simple and clean JS. No compilation step or anything.
Everyone's bar for what is bloat is a bit different. Everyone's definition of simple and clean is different. Typescript, even with a compilation step, is simple and clean to me. Javascript without types is the opposite of simple. Javascript without types is the opposite of clean.
A build system for a simple hello world page is the example I can’t often wipe from my mind.
Reactivity in web apps has been great but around for 20 years already from its roots in Ajax.