Keep in mind there a millions of people who dont need pc or dont want it or whatever other reasons - all they want is to put disc in console and play,without any pc related issues,besides 500 money for a 4K console is pretty good deal,and it will be 450 or even 400 after a year.
No matter what pc "master race" says,proper 4K on pc is extremely expensive,i dont want to go into pc monitors prices at all-recently my new Acer X34 broke after 5.5 weeks of usage,instead of replacement,i just got new 40" 4K HDR TV as monitor for half price - you see where im coming
Im not even talking about 144hz Gsync/free sync 4K monitors,its a rip off.
Another problem with pc is that when some new things coming out,you dont want to stay behind - ok,1080Ti will probably last few years,but not everybody can afford it,so they will keep upgrading yearly,maybe even more often.This isa problem.With console you safe for at least 4-5 years.And its not cost you much.
Overall consoles are very good thing,but gaming industry become little bit lazy and greedy,only few devs using full power even on XB1/PS4Pro,and im not even talking about pc.