Good point. If we look at the previous generations, there isn't that much of a difference between the end of PS3 era and the beginning of PS4 era. The games from 2012 and 2014 look fairly similar. If we compare games from the end of PS3 era and the end of PS4 era however, the difference is huge. Just compare TLoU (the original, no remasters) and TLoU2 for example. Or Dark Souls 1 and Dark Souls 3. Both came out in the middle of their gens, DS1 looks ancient compared to DS3.