Intel doesn't hold anything back. They are limited by manufacturing and their own big hardheadedness. You can't make chips with 250w TDPs, no one is going to buy them lol.
Hyperthreading was dropped b/c it was crap and didn't work. It was made for marketing since AMD was wiping the floor with them. It still has to be turned off for some apps b/c you'll get negative performance. It was reintroduced once they incorporated it into their uarch and software was optimized.
Intel isn't comfortable enough to "hold back". You don't spend billions using illegal and unethical business strategies to knock AMD down b/c you're so secure with your prowess. You do it b/c you're scared.