> admittedly feature bloat, ads, tracking, etc. are also a problem, but I think they're mostly orthogonal to under-the-hood performance
I think for webpages it is the opposite: non-orthogonal in most cases.
If you disable your JS/Ad/...-blocker, and go to pages like Reddit, it is definitely slower and the CPU spikes. Even with a blocker, the page still does a thousand things in the first-party scripts (like tracking mouse movements and such) that slow everything down a lot.
I think for webpages it is the opposite: non-orthogonal in most cases.
If you disable your JS/Ad/...-blocker, and go to pages like Reddit, it is definitely slower and the CPU spikes. Even with a blocker, the page still does a thousand things in the first-party scripts (like tracking mouse movements and such) that slow everything down a lot.