I like a generation to occur when the technology is ready to deliver a significant leap on all fronts. With the rate at which technology is growing, I would like to see generations get even longer, but have optional upgrades like PS4 Pro and XBO X come out more regularly. The next generation is coming about 2 years too early based on what I am seeing. I think a PS4 Premium this year on 7nm with a 3GHz Jaguar and a 10TFLOPs GPU would have suited us just fine, until a full generational leap was ready in 2022.
I really hope that Microsoft and Sony have built the PS5 and Scarlett with many upgraded models in mind. I wouldn't mind upgraded models every 2 - 4 years depending on new tech, with PS6/XB5 not arriving until 2030 at the earliest.
I don't really understand this notion of wanting upgraded models of the same hardware or whatever. PS4 Pro and Xbox One X already kinda boggle my mind in that regard, it's just... isn't it just better to get a PC at that point? To me the whole idea of consoles is that it's this one machine, that no matter where you go or whose console you turn on, it'll run everything exactly the same as yours - that games are built and optimized to perform in a certain way for this one system. Having many different iterations of the same console, with varying degrees of power, it's just a PC thing to me. But, to each their own, I guess.