Comment by dmix

Reactivity as an idea allowed you to manage data and dom/UI updates in a more performant way than the approach prior to React being popular.

But React started a movement where frontend teams were isolated from backend teams (who tend to be more conservative and performance minded), tons of the view was needlessly pushed into browser rendering, every paged started using 20 different JSON endpoints that are often polling/pushing adding overhead etc. So by every measure it made the Web slower and more complicated, in exchange for some slightly easier/cohesive design management (that needs changing yearly).

The particulars on the vdom framework itself are probably not that important in the grand scheme. Unless it's design encourages doing less of those things (which many newer ones do but React is flexible).