All the commercial OSes have limited support cycles. And there are certain inflection points where the newer OS versions drop support for older hardware. Think: Apple's move from 680X0 to Power PC to Intel X86 to Apple's in-house M CPUs. Depending on when you bought your hardware (e g. right before a key hardware shift) you might not get full OS support for the life of the device itself. True for MacOS, iOS and Android.