Someone should tell that to Apple, throwing devices and buying new ones their strategy when the same devices can easily be repaired but repairing things is not encouraged by Apple.
I used the original Pixel for 3 and a half years and at this point it's gotten completely unbearable to use. If it wasn't so I wouldn't have felt forced to upgrade to a phone lacking the features I wanted. Maps takes half a minute to load, the share dialogue is O(n) since the list of targets is regenerated every time you open it, the screen runs at 30FPS or something, taking pictures has several seconds of delay between shutter presses and a quarter of them come out as a solid green, and there's just general slowness of several seconds on nearly every app. And that was after I downgraded to LineageOS from Android 10, when I was getting four hours of standby time (!) and a hole burnt in my pocket.
The thing was as smooth as the OnePlus 7 Pro I'm using now at the time I got it. It was criticized at the time for being overly expensive and an iPhone clone. And now, using it in 2020 feels like using a $20 knockoff device. It was released in 2016. Three years isn't terribly long in the span of human life - at this rate I'll have to buy about 17 new phones if I live another 50 years just to be able to use them at a bearable level of performance. (Certainly a lot of potential money to be extracted for the manufacturers.)
Three years later I'll have to remember this post to see if this still holds true for this new phone.
Also there are practical reasons for this besides social ones (the insistence that OS and hardware refreshes are pushed out yearly or so at the cost of increased CPU and battery usage for existing devices). Flash memory has a limited lifespan and I would imagine it's incredibly cumbersome to replace. It's one of those things where you would just buy a new phone with the money it would cost.
Reusability in the phone market is severely lacking. I run Linux on a ThinkPad manufactured a decade ago and have zero issues running 2020 software. You can't realistically expect to do the same on a smartphone that old. PostmarketOS can't become polished soon enough - I just need to be able to make calls and can't do so using it yet.
The specs are perfectly sufficient to run anything modern. Granted, I don't play games. But browsing, navigating, chatting, watching silly videos, they all work flawlessly. So far, the battery has been holding up, too, even though I use dashcharge all the time.
So that's just that, two data points. I do believe a lot of people could probably fix their phones by hard reset or using Lineage — in turn, that puts the burden on the OEMs to produce good OSs for long-term use. They don't want to, obviously. I don't think the mobile market is FUBAR, but I do agree it's not in the best state. That's not due to the phone per se, it's due to the ridiculous vendor/OS situation we're in with Android.
And don't get me started on security patches…
I did have an awful experience with the original Google Nexus phone and its updates.
Having to install LineageOS just to be able to keep using it invalidates the "first-party" argument though.
Replaceable batteries come with their own trade-offs, namely water intrusion through failing seals. I'd rather pay occasionally for someone skilled to replace the battery than replace the entire phone after a drop in the sink.
Why do I think it is important to be told? My old iPad has almost overnight slowed right down and it is unusable - utterly pointless using it. Why do you think that it slowed down? A new update? Maybe. Or maybe it is the battery. Let me go check... yes, the battery has an issue. Only because I know where to check means that I know how to resolve the issue. And I know that the battery replacement cost will be ridiculously expensive. If I didn't know this then I would buy something else. That's pretty bad.