Literally the only thing that has kept Xbox in the market and selling consoles is their insane commitment to backwards compatibility. Starting during the Xbone's lifetime they were releasing regular updates to the console to get old games working on it. I think by this point the vast majority if not all Xbox games from original to current work on the latest console, and an Xbone before it ended its life was already at most of them.

Its probably one of the only "pro-consumer" moves any of the Big 3 makes, because they aren't really re-producing the games to monetize it and its mostly a purely pro-physical ownership move.