Interesting. That must have been a rare issue. I used a Pixel 5 for three years and followed owner forums pretty closely and that’s a new one to me. I know a small number of people got Pixel 5 phones where the screen wasn’t fully in the frame at one corner but that’s it. Luckily I didn’t have that issue.
So far my Pixel 8 Pro has been pretty good. No bumps. It does get significantly hotter than the Pixel 5 did especially when charging.
I’m curious what hardware issue you had with the Pixel 5. Mine was great.
Just because you can’t see them easily doesn’t mean they aren’t a problem. Enough pressure on the back of the screen to cause bumps like that could cause issues with the screen. I’d definitely send that back. Luckily mine has no issue and based on the 12 Pixel 8 phones I’ve seen (including mine, a co-worker’s and phones in stores) and all the owner comments I’ve read it does seem to be rare to have those bumps.
Enough pressure on the OLED panel to not only indent the panel but the glass as well is definitely something to worry about. That much pressure could definitely cause issues in the future. If my phone had those bumps I would have sent gotten a replacement.