Pixels get first class support by google in terms of software which means I can rock my phone for several generations before upgrading.

I've owned a 2, 6, and now 9. Even though the 9 is much faster than the 2 or 6, I've reached a point where that performance difference simply doesn't matter. I'm not being held back by the CPU in any real way. That leaves security, software, and battery life as the main reasons why I might decide to update my phone.