At 6TF, Microsoft basically cornered the competitors before the next generation even started in the first place. Jumping much higher after this yields negligible benefits to performance, and the cost will skyrocket afterwards. Attempting to go further might be costly, so Sony either needs to find a way to be better which precludes power, or risk MS starting with an already vast catalog and around a million or more users.
They actually played a good hand this time. They did something that would ensure they remained the top dog one way or another once this generation ends...
Are you just talking about the remainder of this generation and the small possibility of another mid gen console or are you suggesting that the difference between the X and 7nm next gen consoles will be negligible?