I already happened to go over 60G of used space (before a large clean session)
But I also test a lot of new packaged apps.
Anyhow, the / use trend is up, thus it’s safer to use “a lot” than to have to repartition later on !
I use the same size for my Debian.
OK, we’ve split off the question about sizing from the main topic that was being discussed!
I’ve written about this previously for my previous OS and based that article on research: what vendors recommend as “minimum” and “recommended”
However, as we both now those are too low for power users and as you pointed out users that test systems have even higher demands of their system.