128GB is not enough in this days, not even 256Gb is not enough. 500GB is ok.
It would appear thats not what Apple wants you to believe otherwise why would they sell it. Most people know why - as it would promote their cloud services etc.
Anyways I dont care. 128GB is plenty for me only if the macOS would allow me to use it without regular maintenance like purging the local snaps
I refuse to make an already exorbitant purchase more of it by pouring in more money on the next higher capacity model (is it 200USD/EUR more for the 256 model?) because macOS does certain things in peculiar way and make space for it -LOL. The problem lies in there - in the OS.
e.g. yesterday I deleted a ~9 GB local snapshot!! Auto back up is OFF in TM prefs.
I wouldn't be writing this if it were a few hundred MBs of smart file versioning/history but 9 gbs?