Unfortunately, the headerbars are really that big for normal (not using CSD) apps. And no, this is not a trivial issue. I know several persons for whom big headerbars were one of the serious reasons to reject using Ubuntu. These needlessly wide headers are really ugly and this is indeed one of the reasons why people hate modern Ubuntu.
The discussions here about wide headers normally end up with the argument of “visual consistency”. I believe that hatred towards the whole system is too high price for the doubtful “visual consistency”.
Just get me right, I do like Yaru very much. Both icons and window theming. But these headerbars… so space-eating and ugly…