‘He’s not that much better’ (not that much + COMPARATIVE)

  Yardbarker
The Bears’ quarterback has been better of late, but not that much better.
*’of late‘ means recently.

Point 78 in ADJECTIVES/comparatives is defined as:

‘not that much’ to modify comparative adjectives to a small degree

in iWeb:

1 NOT THAT MUCH BETTER 280
2 NOT THAT MUCH BIGGER 109

It’s just not that much bigger.

gundogsupply.com

(listen to a similar sentence)

3 NOT THAT MUCH HIGHER 98