Not a chance the PS5/Scarlet are equivalent to an RTX 2080. The RX 5700 XT is the best Navi card atm, it's not as good as an RTX 2080 and it costs $400.
Performance will be closer to the RTX 2060, a little below the RX 5700 (non XT).
Next gen consoles will have hardware capable of ray tracing, so their GPUs will likely be based on AMD's next gen architecture, not the actual. That's not to say that they'll be as powerful as a 2080, of course, there are a lot of reasons why that isn't realistic (cost and heat are the obvious ones), but we have to keep that in mind.
We also need to remember that PS5/Scarlet will probably target 4K as their goal resolution, and that demands a lot of power (unless they go for a checkerboard trick again).
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.