Funny, this is how I (and I think most people I've worked with/for) describe a mid-level dev. "Doing the thing" is a pretty low bar but we don't really expect that from juniors, who typically need hand-holding. To be a mid-level you should be able to operate independently and provide optimal or near-optimal solutions most of the time, but your work is still going to be just focused around you. Most of what you're doing is individual tickets, refactoring, etc., nothing that influences or impacts the broader team. When your impact is beyond your individual work is when you start moving into the realm of senior, and it's part of why it takes time (not just skill) to get there.