There's some truth to your comment though, in that VSCode's optimizations are very on rails, i.e., if you go the slightest bit off the beaten path (like I opened a file from the Finder, instead of from the sidebar, in the BBEdit/VSCode video), then VSCode approach to optimization falls apart (you can find accounts of the tricks VSCode uses to appear fast online, there's a lot of smoke and mirrors based around specific workflows -- I think making a new tab is actually the example they use). It wouldn't surprise me if part of the reason I perceive it as so slow is I expect every feature to be fast, not just to most common ones. And I think this is a perfectly fair metric to measure by. Emacs, Vim, BBEdit, and Sublime Text are all fast at everything they do, therefore I think it's fair to call VSCode a slow editor, even if technically it's average for a couple of features.

Granted, it's not a high-end workstation, just a laptop from 2016. But I don't think it's slow; when Vim first released it could have beaten the fastest supercomputer. Now of course that's a matter of perspective, but I hope I'm not the only one who thinks editing a package.json shouldn't make any modern PC sweat.