[emerongi]

Browsers also don't provide the necessary tools to actually build interactive UIs without reaching for external libraries. If you want to allow the user to select date or time in a decent user-friendly way... you just have to pull some JS thing in. Dropdowns/select boxes still only provide the most basic capability; multiselect sucks, need to pull in another JS thing. The list can go on.

Even if your application is 90% non-interactive, the remaining 10% could end up introducing a lot of complexity only because browsers haven't advanced on that front at all in the past decade. And that 10% could easily outweigh the 90% when it comes to the architecture of your application - you get frustrated with the jumblefuck of JS littered randomly around to support X feature on Y page and so you just grab React and build a more manageable thing with it.

The standards committees for the Web have seriously dropped the ball.