I saw someone post on a non work slack about their steam library, where they had a bunch of games that previously ran on mac, being decimated, and they meant decimated literally by catalina. 90% of their games were 32 bit.
The good news for steam users is that you don’t have to purchase the game separately for each platform. The decimated users can build their own Windows gaming PC and easily regain access to all of their old games. I doubt they had any Mac-exclusive games that also happened to be 32-bit only. Do such games even exist? Maybe.
Funnily enough that is the inverse of the historical meaning of decimated (to destroy 10% of something).