In VSCode, you can enable multiple cursors by clicking on the desired positions while holding down Alt/Option. I think they're enabled by default when making block selections (CBA to remember the modifiers you have to press while drawing a selection with the mouse). And to cover a whole file, first use Find to find the thing you want to change, then hit Alt/Option+Enter to select every instance of the subject string. Now any edit you make will affect every instance.

Basic stuff, but I see a lot of people not really taking advantage of the tools they might've been using for years.