> Heavy software users spend hours within are where those hundreds of milliseconds per action really add up. We should be angry about anything worse than single digit milliseconds with these tools.

I think in the article writers mind here we are talking hundreds of milliseconds on first load and the majority of actions are instantaneous after that.

This can be achieved, but it takes some diligence and product mind focus to optimize what you can how you can and even big companies like Google don’t always prioritize this the way they should