I have an iPad from 2013 that works just fine. It only runs iOS 12.5.5, so some modern apps using newer APIs one cannot install. But many things run perfectly ok, just a tad slow. And, if an app doesn't run, the App store offers to install the latest version still compatible with the OS, if available. I don't see how that's compatible with your claim that:
> as soon as they stop supporting it, that's it, you now have a brick