You may be broadly correct, but “macOS has always been free” is definitely not true: all the Big Cat releases of Mac OS X were paid-for, right up until MacOS X 10.8 “Mountain Lion” released in 2012. Only later, from Mavericks in 2013 onwards, were upgrades free. And further back in time I remember buying a software update for my first-generation iPod Touch up to par with the first-generation iPhone way back in 2008. Apple still sells or provides subscriptions to a lot of software (Final Cut Pro, Logic, et cetera) and back in the day I paid a lot of money for some of their more niche offerings Xsan, for example, which I remember cost me an eye-watering thousand bucks per node. Xgrid on the other hand was free, and it’s extremely unfortunate they killed it because in this day and age of Thunderbolt-interconnected Mac Studios with unified memory architectures running AI workloads “here’s a bunch of Macs regard them as a unified computing resource” would be extremely useful (but I digress from the digression).

Logic, Final Cut, Xcode etc aren’t really the same thing because they’re applications rather than the OS (which we were talking about).

But i didn’t realise Apple used to charge for OS upgrades. So thanks for the correction there.