In the end, the only difference between one gen from another gen is exclusive games taking full advantage of said hardware. The games that have to work on both models and are designed in that manner are cross gen.
I never understand that line of thinking though, because PC games take "full advantage" of top tech, but also run on older spec machines. I dont see why we cant do that with consoles now, and be able to upgrade to a newer spec machine every few years. all your old games still work, but you also get the best of the best when the new stuff comes out