How often do you buy a new main television? And I bet the only reason you change your phone so often is because it's subsidised through contracts, tariffs etc. Also, most people don't actually change their PC components every 2-3 years, except the enthusiast market, or if a component actually fails. People need to stop comparing consoles to other iterative technologies, they are not the same thing. One of the main draws of console gaming has been the value for money and longevity of the console hardware cycles, as well as the closed platform focus, and knowing your money will go a longer way. With older console cycles, slim models were generally introduced around this time frame, but that didn't impede on vanilla users quite the same way, as the hardware and gaming performance itself was exactly the same, so those older customers never felt left behind. This new iterative direction changes that.
With all that being said, I don't think the PS4K will necessarily fail, in-fact I feel it'll probably do quite well. I do however think Sony is also going to garner a lot of ill will from existing customers, and a large swath of their consumers will see less value in future purchases of their console products. At the end of the day, for the casual consumer, why buy a PS5 if there is a risk of PS5.2 only a few years later? You either just wait for the new version to buy the more powerful hardware, or wait for the new version to pick up the older machine for dirt cheap. Either way, I think this iterative strategy may prevent Sony from having the same sort of initial momentum it did with the PS2, PS4 etc, with new console releases.