If you want a top flagship, I agree Apple is a solid choice. What Xiaomi and Android does well in general is midrange. I've got a ~$150 phone (Xiaomi Redmi Note 4, now superseded) that has fantastic performance (never had any issues with tens of tabs in browsers, multitasking, games, etc), fingerprint sensor, battery lasts for 2/3 days, etc. You can tell it's not a flagship: the camera is just tolerable, it's got a plastic back (which doesn't break after repeated falls); but overall it's insane value/cost.

It's nice to surf the wonders of billion-scale device mass-manufacturing if you don't need the latest and greatest.