Most people are “okay” with waiting 500ms for a right-click context menu to appear,

It is maybe that most people have never experienced the world "before" where everything in term of UI was a lot faster than today when we were more using real native applications.

I have often this debate with friends that think VSCode and co are awesome when for me it is barely usable to have an editor with so much latency on each key typed.

Same effects with apps like mail clients. When you are in Gmail and struggle to select hundreds of spam in multiple pages to delete them, compare that to the instant click/drag select of emails with infinite scrolling in native applications like thunderbird.