I got a OnePlus 9 for this exact purpose and it was good, but not without issues. Same thing as what people said back in the early Linux days - buy what the developers have. Custom Android OS developers overwhelmingly focus on the Pixel, and the hardware is decent enough, so that's what there's an ecosystem for.

That OnePlus 9 had some weird issues that eventually got resolved but it took a while. Important to differentiate between an OS that builds for a phone and one that actually works for a phone, but there's not usually a ton of reviews for the latter.