Your 1070 wouldn't even run 30 fps at 1080p at ultra settings in newer games that push gpu performance, who gives a shit about lower settings its a next gen machine.
PS5 is underpowered on the GPU front it's not even questionable really. I dunno why this topic starter has the delusion that 9-10 tflop gpu in the PS5 is going to perform like a 2080ti which by the way sits at ~14+ tflops and has like 500-600 gb's dedicated memory unlike PS5 shared memory at lower clocks, it never will. There is a reason even DF didn't burn their bridges with even stating that the xbox series X sits at 2080ti levels, because that would simple be false.
DF + the dev that worked on it
skip to 12:45
5700xt by the way, hovers average 20 on a current gen title. ( heavily favoring AMD by the way )
Welcome in current gen 4k newer titles that actually pushes hardware.
We also don't know what RDNA2 will give us and to what extent it favors those GPU's. As the 5700xt sits at 270 watt peeks, and with higher clocks, u could see all the performance per watt disappear in thin air by simple lowering the wattage to keep things cool. But frankly even if it did move stuff up it won't be much more than what a 5700xt is going to deliver at the end of the day.
That GPU in the PS5 sits pretty much somewhere between 2070 and 2070 super and that's what u should expect.
Now lets get back to power of that GPU and how it compares to last generation:
Xbox 360 vs PS4 = ~7 times gpu performance increase with ~2x increase in resolution.
PS4 vs PS5 = ~6 times gpu performance at absolute best, with 4x increase in resolution ( and then the discussion about double the fps with it oke man )
Doesn't take a rocket scientist to see how the GPU for a next generation 7 year long period is going to cripple the living shit out of that box when the focus is 4k. It's underpowered as hell for it.
The PS5 GPU towards 4k is what a 1060 is towards 1080p right now.
There is a reason cerny clocked that gpu to hell, they need all the performance they can get.