There is absolutely no way mge doesn't doesn't help your actual aim and understanding of movement, especially as a new player. However, youll get to a point where youll realize just because you beat somebody in mge doesn't mean you can 1v1 them in real games the same, because mge is really forced. Despite this, mge is always helpful for a new player; the most important thing you should get from it is an understanding of movement. on top of that, it's just good practice for aiming.
There are plenty of invite players who have never really mge'd much though, but then again, I've seen an invite player who was known for their dm be that "bad" at mge. It's just a useful tool if you can find some joy in it when playing with friends.