Interesting review, I think the line that immediately resonated with me was...
I had two immediate observations: the Pixel 4 XL’s display is much dimmer and muted than the (usually) vibrant OnePlus 7T display and is clearly a step down. And the general design of the Pixel 4 XL is bland and unexceptional
I have a 4XL and S20+ and very recently had the OnePlus 7 Pro, I really should sell one as I flip-flop between them. I love my 4XL but there is something unremarkable about it and I think the line above and the comments on size do lead to that, it does feel dim and it does feel a little small. When I pick up the S20+ it feels night and day like a 2020 device vs. if I am being cruel a 2018 one but then the camera is so inconsistent and I find the software and gesture implementation make it all feel a little disjointed.