[karthink]

> It's definitely slower when doing any intensive background activities that Emacs would normally offload.

Emacs is single threaded and can't offload any elisp code. Even the stuff it can offload as background OS processes report in to the main loop and share time with editing, so a chatty background process can and does frequently lock up Emacs. So I'm surprised that VSCode, whose runtime is better suited to async jobs, ever feels slower than Emacs.