I’m already living on a Fil-C compiled CPython. It doesn’t matter.

And a Fil-C compiled text editor. Not VSCode, but still

I absolutely do think you could make the browser 5x slower (in CPU time - not in IO time) and you wouldn’t care. For example Lockdown Mode really doesn’t change your UX. Or using a browser on a 5x slower computer. You barely notice.

And most of the extant C++ code doesn’t fit into any of the categories you listed.