I've been using vim pretty much full time since around 2000. The one important thing to accept about it: you'll never know all of it. It's just huge. (but you'll never know all of any big dev environment - such is the life of a software dev). To get really good with it, after the basics, I just kept (and still do) in mind that "there's probably a better/easier/faster way to do this". Then roughly once a quarter I'll spend an afternoon figuring out how to do something new, and consciously focus on incorporating it into my workflow. Just like I would with any other tool or technique.

Just because it's "old school stuff like vim" doesn't mean it isn't worth learning. I don't know how it's viewed so differently than say, learning how to use containers, or learning how to do event based programming, or any other concept that slows you down for a little before making you more productive.