alt Hacker NewsWhat's reactivity in this context? How quickly a website responds? My personal experience is that fast backends with server side rendered HTML and a bit of dynamic sections are in practice MUCH faster than SPAs, 20 years after using Gmail for the first time. Gmail then was fast, 95% of modern SPAs are slow.
Reactivity is updating the DOM whenever the underlying data is updated. That's one of the most basic reason for existence of all js frameworks. There's TC39 Signals proposal to bring that natively, but for now as said above the choice is either use a framework or recreate one. It's surprisingly easy nowadays using Proxy.