Curb your expectations. You're getting iterative from now on, with smaller more sensible upgrades each time
That's not true since Andrew house says the exact opposite of what your saying in terms of iteration.
If your point is that 'generational upgrades' on the scale that we know them are done, that's common sense due to how components are advancing. By default, we will not have more than double to 3x the amount of RAM in a hypothetical PS5(compared to 10x from PS3 to PS4), and the GPU in 2019 may be able to hit 10+tflops, but to get anywhere close to 10x, like PS3 to PS4, would mean getting close to 20tflops which would be impossible outside of the biggest dedicated GPU's i feel. So the jumps are def getting smaller and smaller in certain ways.
But trying to equate a PS4 to NEO like upgrade to PS5 i think is unfounded.
NEO uses the same parts marginally upclocked, and a better GPU, a N3DS type upgrade rather than a brand new console.
If PS5 uses Zen, 16-24GB HBM3 and whatever mid to high end GPU is available at the time, that will be a generation level jump in terms of CPU power, memory bandwidth and even GPU architecture, let alone a significant RAM increase.
My point being, don't expect PS5 to follow generations past in ters of multipliers, but the power differential will still be significantly more than what an iterative unit like NEO would present. That i think is what Sony will try to illustrate in the difference between a numbered mainline PS console and a NEO iterative unit in 2019-2020.