In a few weeks, 1% of creators already using YouTube Studio will no longer see the ‘back to Classic’ button – you’ll be notified 1st & can still access Classic features you need! This won’t apply to everyone else until early next year. More info → https://yt.be/help/a7mG
Why not just keep the classic one, it’s the one most people are used to using, I’ve never used YouTube studio, and always go to the classic studio