Treating 10KB of JavaScript as equal to 10KB of HTML is a big mistake. They transition over a network in the same amount of time, but HTML is far faster to process. Websites with large HTML sizes often display far faster than the same information that use JavaScript client-side frameworks. Often the framework is still trying to figure out which way is up, while the HTML version is already being displayed. It's a trade-off that isn't discussed enough.

I wrote a game engine with a DSL that renders as detail/summary html blocks. It wasn't hard to end up with a page that was hundreds (or thousands) of megabytes. Any given browser really had no issue until it was over several hundred megabytes.