In Javascript, maybe, but frameworks like WebForms already had 1st-party components (called "user controls") back in the early 2000s. Granted, it was server-sid

In Javascript, maybe, but frameworks like WebForms already had 1st-party components (called "user controls") back in the early 2000s. Granted, it was server-side only. Hooks are a tough one (they're very specific to reactive frameworks), but we did have other kinds of abstractions that provided similar benefits.