Earlier quoted context omitted.
It's really no secret after all these years that you need to buy a Google phone to get best support for their OS, just like you need to buy an Apple hardware to get support for their OS.
I bought a Nokia 6.1 around 2 years ago, which is part of the Android One program and it worked well! Had all security monthly updates, the system is clean and stable, updated to major versions of Android smoothly without any issue. If I can, I will buy another Android One phone. There is an horror story about an Android One Xiaomi phone, but Nokia delivered the promise with the 6.1, according to my experience
Which one? I had a Xiaomi Mi A1 and nowadays I have a A2, both are fine Android One phones that still receives updates (in the case of A1, only security ones, but the A2 received a Android 10 update).
Yeah, Xiaomi may take a while to update their phones in Android One program, but otherwise it is fine.