For me the comparison should be early 360/ps3 to early ps4/xboxone. If you look at it like that the graphical jump it is kind of ridiculous. Seeing a bit of game development this gen, the biggest change is that since the old generation went on far too long, everyone got too used to cadence and iteration they had before. Say if a game cost X amount to make during end of 360/ps3 era it probably cost 2X-3X more now because of all the additional cost you have for art assets (for examples charecter models have so much more detail in most games now, its just one of those things that you don't really notice unless you can zoom in and see the skin features cause most games are played from a perspective that is pretty zoomed out) and the lack of best practices and optimization that game developer created over a 8 year console cycle. Hence why we got all the delays last few years, it's freaking rough making AAA games now days.
Games will start looking crazy good sooner than later, but because of various reason listed (most of which have already been mentioned) it will take longer than last gen did. Plus the biggest jump for me is in the console\ infrastructure and its online capabilities that can be hugely expanded with software, where last gen those infrastructures were not in place and were kind of forced in via software.