I'm at 1620 in my HRE game and, for me at least, it's gotten better.
By leaving some powers unmolested (Spain, England, Russia) They've started blobbing and colonizing and are now almost able to fight me (I still have 3 times any of their incomes though, but they're catching up every year, even as I keep conquering other areas.) As long as you don't don't try to destroy them, you can have some fun rilvarly.
Don't try the BB idea. You'll win the punitive wars, and your country will just constantly be rebels popping up and stability going down. None of it will kill you, but there's nothing to do then.