It seems that if you could still buy macOS separately you could buy more copies than computers and lease these out for 24h while sharing the hardware with much

It seems that if you could still buy macOS separately you could buy more copies than computers and lease these out for 24h while sharing the hardware with much higher granularity which would lower the cost significantly. However it seems that no version of macOS since Lion (2011) is available to be purchased standalone anymore. It is a shame that Apple forces such a wasteful and inconvenient process but it is more profitable for them and apparently they are legally allowed to do so.