As a counterpoint, my gf replaced her OnePlus 5 with a Pixel 4a and hasn't liked the move. Other than the camera sensor being better on the 4a, she preferred the OP5 experience.
My OP5 will eventually be replaced, no idea what with. It's the perfect size to me, kind of a medium phone. Bigger than the 4a by a bit, smaller than most other smartphones. I'd mainly be upgrading it for a newer camera.