From the wording of the parent comment my understanding is that 24 hour period applies to the MacOS VM, not the hardware itself. Since they split each physical host into at least 2 different VMs the 24 hour period is for that VM. Even stronger case if they also lock the core affinity to the physical layout like Max editions having multiple Pro chips/dies within...

For Amazon EC2 the case is different since it doesn't allow VMs but only possible to get dedicated bare-metal hosts. Obviously Amazon could offer VMs but they would not because the current way allows them to charge 24 hours even if user uses the host only 1 hour. And obviously no body big enough challenging the status quo and impacting AWS' revenue hard enough.