I think this is possibly the wrong way to look at it. Both Pycharm (and the JetBrains core IDE) and Vim have large feature sets and those feature sets can be e

I think this is possibly the wrong way to look at it. Both Pycharm (and the JetBrains core IDE) and Vim have large feature sets and those feature sets can be extended via plugins. So saying what you would gain from one to the other is not straight forward. You gain some things and loose others. For example Vim keeps it's undo system as a tree whereas most GUI apps keep their undo commands as a stack. i.e. if you have series of edits and you undo 2 and then make a new change the other two edits are lost. In Vim they aren't, the tree of edits can be navigated at will. Assuming that undo tree is a useful feature to you (it is for me) I'd have to do a good search of Pycharm plugins before I can say it's a definite advantage of Vim. Equally you might find that Pycharm has some code aware feature that Vim can't provide via an LSP plugin or VS Code extension in which case you'd want to stay using Pycharm.