It's a perfectly fair comparison. I can go all the way back to the Adam being better value/performance than the 2600 because of better CPU/GPU if you want me to continue using your logic. Those are perfectly legitimate analogies.
The Wii U and Vita were flops too but they can also be part of the discussion. The fact that you admit the flops above proves that you understand that CPU/GPU "specs" (because again, PS5's CPU/GPU specs are inferior to the Series X but we can plainly see the PS5 is better in that regard anyway) don't determine the value of a console. The market determined that these consoles, despite their specs (both were #1 in their category CPU/GPU wise upon release), did not have sufficient value - their performance as gaming machines was lacking. The market determined that the value and gaming performance the Wii and Switch offer are good value.
For what it's worth,the Switch was top line CPU and GPU wise for a consumer gaming device in 2017. A hypothetical Vita 2 would have been in a similar power bracket if it released in 2017. As far as the price goes, mobile costs more. It's a feature with value that is reflected in the price. Let me know when I can play my PS5 with nothing attached on a plane like I played local co-op Mario Kart on my Switch in a plane.
For the record, I actually *can* play Scarlet Nexus on a plane with my laptop - at 1080p and 60fps (I might even be able to get more fps if I wanted, because my laptop's GPU laughs at that game). That laptop costs a lot more than the MSRP of a PS5 though, because portability and the general purpose nature of the laptop costs, but those are values I'm paying for, even if the PS5 has a better GPU in the end. (Definitely doesn't have a better CPU).