I'd argue a problem with Android and Apple is that their Platform API are not Modular like Microsoft' Windows SDK.
What I mean is that Microsoft Store also has a feature that will hide Incompatible Apps from various devices.
Now I won't bother delving into that as AppGameKit doesn't support (WinRT / UWP), just keep in mind while a similar concept works quite differently.
Still, I would point out that the concept that AppGameKit itself takes of "Widest Support" is a false idea and not one that you as a Developer should NOT
What I mean is the concept of people keeping their Handsets for as long as possible is an archaic concept that WE
might've become accustomed to, because until the advent of the Smart Phone the concept of "Upgrades" being part of a Mobile Contract was rare.
You typically would pay for your Contract and would get a DISCOUNT on Upgrades, but they wouldn't be provided Free.
Today however... even on the Budget Contracts., once you hit 18 - 24 months you're offered a Free Upgrade to the latest Model in the same Tier as the one you got with the Contract.
While PAYG used to be common., at least within Europe and South America... today this has changed since the advent of Smart Phones.
Simply do a survey of your Friends and Family... see how many of them have Handsets that are over 3 years old.
I guarantee you such individuals will be outliers and more importantly will NOT
be Gaming on their Mobile Device.
Remember the Mobile Phone Market is at present approx. 4.6 Billion Devices., and 1.8 Billion Devices are Shipped each year.
Most Suppliers either deliberately or simply can't keep produce to meet Demand.
So, you're looking at almost 40% of the Device Market being Supplied each Year., you think they'd do that if they weren't shifting inventory?
Some is going to be Failure Rates (up to 3% is typically "Acceptable"), Some will be New Customers (at this point we're at Saturation Point, so again we're looking at maybe 2-3%), Some will be as Repair Components (maybe 5%) from Damaged Handsets; especially since more are being produced as "Sealed" Units as opposed to easily repairable / replaceable components.
So what are we down to... what 30% of the Market having a new Handset each Year., and you consider the 18-24 month Upgrade eligibility; well this heavily suggests MOST are on a Handset at most 3 years old.
That's what you should be targeting.