Re: "Earlier this year it slashed the length of support perpetual licence holders could expect."
I agree that the OS support from Apple in terms of security updates is better. The far bigger issue is whether the Apps are supported on the older versions of the OS.
This came to light when I was assisting a friend who needed to get their Mother some basic connectivity on a tablet.
I have had very little to do with Apple but believed stuff about "longevity". Now this all when pear shaped when the old iPad could not be updated beyond a certain version of iOS. The apps they wanted to used could not be installed because the version of iOS was too old.
There is much to this than just having security patches.