I'm totally with you, with that article. It is terrible how owners of slightly-old hardware are treated by software developers. Leaving potentially millions of users out in the cold because they just can't be bothered to keep a maintenance branch around and backport a few fixes to it. For apps that are by and large not complicated. So much waste sacrificed at the altar of developer comfort!
My low-end test unit is an old SE (running 15). I'm an iOS native developer. The screen size is the main reason I test with it.
However, these days, I usually release with minimum support beginning with iOS 16, because I am a one-man shop.
My stuff will usually run in 15, though.