As for what do you gain, it's basically the same jump as copypasting by using ctrl+c/ ctrl+v vs. using your mouse to go to the top bar and clicking edit-> copy

As for what do you gain, it's basically the same jump as copypasting by using ctrl+c/ ctrl+v vs. using your mouse to go to the top bar and clicking edit-> copy then edit->paste. What I mean is that it's one of those computer skills that, after you learn it, even watching over the shoulder of someone who doesn't use it is painful. As for vim vs pycharm, I wouldn't advise to switch. I would advice to find vim emulation for your current editor (vscode's is superb).