The existing UI is awesome, why are you messing with it and ruining your product?
I like the old textual panels, they are compact and descriptive, I can organize them to my liking. I don't like these large icons and I do not understand what do they mean. I need to click and guess to find a panel I want. I don't like the amount of space these panels take.
I don't like that hamburger popup menu. Who gave you idea that a smartphone style popup menu is a good idea for a desktop product?
I'm sure that third-party plugin developers won't be dedicating much effort to own icons with consistent design, so all these panels will look like a crap zoo of ugly icons of different shapes and sizes.
I've been using JetBrains products since 2004 (ReSharper) and 2009 (IDEA) and you're destroying everything.
Find another way to occupy yourself, put your hands off the existing UI, no one asked you to do it, so just don't do it. Don't fix something that isn't broken.
If you want it to look like VS Code, then I will rather cancel my subscription and switch to VS Code. At least they have a larger community for the same iconish UI.