Unless you have spaghetti code or have built an abstraction tower, a variable is probably scoped/namespaced neatly. Often, it's just a quick grep to find it. In Emacs, if a variable is only used within a file, you can just `M-x occur` and do the editing there. Where those tools fail, is when you have ecosystems that tries to be clever (JavaScript with its transpilers, Java with its annotations)

Yes, but not everyone uses features like this to make code easier to read. Instead, features like this make less readable code become tractible. The same can be said about autocomplete and documentation popups too. I remember Uncle Bob saying once that his 5 line function limit was facilitated by an editor feature he had that could easily display the code of functions that are called. So it stands to reason that the recommendation should be 25 lines if you don't have such a feature, I think. We don't need to go back to Hungarian notation but certainly using a bunch of fancy features to read the code makes it inherently less readable on the surface level (unless you are very anal and also self-aware and can stick to clean principles).

I'm surprised my comment was downvoted so bad for making an astute observation. It happens to me all the time. A lot of the users of this site suck.