The Note 20 module actually looks smaller and maybe thinner than the Fold 2 setup... if you're gonna put a bump like that on a $2000 phone, it better be high end!
That being said, maybe they couldn't get a more powerful setup all sorted out in time. I mean look at the N20U setup and there were reviewers saying that the camera has a shutter lag problem. And that's with the highest of specs, latest SD and 6.9" screen. Now imagine them getting it to work on a 7.6" panel all smooth, etc. Has to be a ton of procesing power and the experience could have been janky. Just a guess.
Still worlds better than the 1st gen setup.