I think the challenge is: Does your hardware support the updates? Hardware vendors from time to time have the tendency to change the OS in ways that it works nice on brand new hardware but is very sluggish on older hardware - to the point of being unusable.
So if I get an update 6 years in that renders my phone unusable, I haven't gained anything.
I would prefer 7 years of sec updates in that case.
>>KingOf+(OP)
That might be part of their calculation. After five years or so, most people aren't going to want them. So they might run poorly, but at least they're not abandoning them.
Anyway, it was mostly Qualcomm that was preventing longer upgrades, so I respect them for finding a way out of that. Maybe Qualcomm will now have to support their chips longer, due to new expectations.