It's amazing how much people under estimate the power of only having to develop for one/two locked in platforms... For PC, developers have to take into account thousands of possible combinations of hardware.
Regarding TVs, pretty much any decent high end TV for £500 will look far superior than any current monitor even in normal/SDR mode. For a gaming PC, you need to be spending at least £300 for a decent monitor and for IQ, it will still look trash compared to a TV, let alone a £1400 OLED 55" 4k HDR TV (I would actually say that an OLED TV paired with a PS 4 PRO/xbox 1 x would still look visually better than any game maxed on the PC on any current LCD monitor), only advantage of gaming monitors are 100+HZ (which is mainly only beneficial for low input lag, this will help motion clarity to if you hit the FPS but some TVs are superb for how they handle motion even with 30 FPS), free/g sync.
Of course, you can pair your PC to the TV too but it isn't easy for many people considering the size of "most" gaming PCs + most people have their gaming PCs in a different room to their main TV.
There is just no way you can build a complete PC that matches a xbox1x for £500, it just isn't doable, CPU, MB, RAM, GPU, 1TB hard drive, monitor, mouse + keyboard, windows OS, speakers/headphones, PSU, case.....