However you have to take into consideration what the OS updates do on each device.
On iOS, an update also updates all the system apps, meaning Safari, Maps, weather, notes, mail, health, photos, the calculator and so on are hyper dependent on having OS updates for a long time.
On Android, all of those system apps are updated via the play store, and a lot of deeper features can be updated via Google Play services similarly to how Nearby share was able to be back ported to any Android device running 6.0 or newer when it came out recently. Full OS updates are still important for Android, but they aren’t nearly as critical to the overall user experience.
I use an iPhone, but I’d love them to move all system app updates into the App Store for more frequent updates. The only plus side to the way Apple does it is that everyone gets the update at the same time and you don’t have annoying staged rollouts like you do with Google apps.