After two years with my amazing Pixel 6 Pro, I traded it in for a Pixel 8 Pro. There was nothing actually deficient about the other phone. The battery was maybe not quite as robust as it used to be, but even with heavy use (because of crossword puzzles), I was typically ending the day with 40%. But once again the incentives to upgrade were too good to pass up. This time it involved a $400 credit for the old phone, which will not last given its age, and a free Pixel Watch 2, which I knew Diana would get a lot of benefit from, as she works on her feet. So in that sense, it was kind of like the phone only cost $250, and that means a fresh battery, updated processor, brighter screen, better cameras and all of the computational photo magic.
The upgrades in phones are mostly incremental. There are no "big bangs" to make. The longest I've had any phone was about three and a half years, but my typical cycle is two. On this cycle, I was actually confident that it would be fine for another year or two, and I think part of the thing now is that they use dynamic charging. Basically they charge slow overnight, leading up to your alarm time. Slow charging is better for batteries, which are really the only limiting factor of phones, short of dropping them and breaking them. The weird thing is that Google is promising seven years of updates this time around, which seems meaningless because I can't imagine anyone would keep one that long. But I'd like to go three this time.
I don't like the seemingly disposable nature of these devices, because electronic waste is particularly bad for the environment, and there's a lot of stuff in them that is valuable to recycle. The EPA says that less than 20% of phones are recycled, which seems like a pretty terrible ratio, especially since so many carriers and manufacturers have trades programs. Samsung, Apple and Google all have these programs, and I believe all of the carriers with physical stores do as well. I've recycled my previous five phones, all sent back to Google.