On other side update iphone 4s (2011) to ios 8 (2014) makes it horribly slow, while technically still 'works'.

Its even worse than that. Apple blocks you from going back to the older version of the OS. I had to literally throw away my 4s, (it was working fine otherwise) because it had become unusable for me after updating the OS.

The primary cause of that sort of thing appears to be the significant leaps forward[0] they've made with their ARM hardware every year.

At some point it will plateau the way PC hardware has, and new major OS versions won't be as much an issue.

[0] https://arstechnica.com/apple/2017/06/review-10-5-inch-ipad-...

On the other hand, my iPhone 5 from 2012 is still plenty fast on iOS 10.

It's good to hear that. At some point their OS updates did break that tradition. But I do remember people with an old iMac (1st gen maybe) who enjoyed getting OS X support until very far down the road. Considering the pace of change and the limited hardware I was pretty stumped. It was a slower, but usable, and new features made it worth the cost.

Windows rarely felt that way. Linux does feel this way most of the time if your needs are "tech saavy". If people could register that a recent eOS, arch+gnome3 or mint+xfce can make their machine fast, cute and even more functional than ever ... I try to show them but they fall into the grumpy reflex (ewwww that key doesn't do what it did, delete linux !)

They are definitely doing better than before, though considering they essentially replaced their OS with 10.0, and then went through a whole architecture change to Intel, I still have to give them props.

The PPC to Intel migration was handled beautifully. Rosetta was straight up magic. It "just worked" and was around a few versions.

Intel Clover is not even a different architecture, it's still x86. Makes me wonder if (and believe that) Microsoft could've made this transition more graceful had they wanted to.

I still use my mid-2010 17" MBP, fully up-to-date on the newest OS release. It's showing its age, but still gets the job done.

Complexities aside, Apple keeps things running. I have never had to worry about my MBP simply failing to work due to OS compatibility issues.

I still use my early-2004 15" Thinkpad T42p, fully up-to-date on the newest OS (Debian Sid) release. It is showing its age - mostly when browsing JS-encumbered sites - but still gets the job done. I have never had to worry about my T42p simply failing to work due to OS compatibility issues.

Of course this machine was expensive when new, just like Apple-branded hardware is expensive. Sometimes all that money buys you something worthwhile like your 7 year old MBP or my 13 year old T42p. Other times it is just a lot of money down the drain like I expect the recent touch-strip-addled MBP series or any machine which has consumables glued in-place to keep pesky users from getting a few more years out of their investments.

Isn't this for the same reason that iOS can be quicker than Android, because Apple control the hardware and can thus optimise and focus their efforts?

Yeah, they are much more focused and control the whole stack (especially in iOS, where they build the SoC too) from hardware to applications.

I would imagine that vast majority of similarly aged (and older) PCs that are in the same price bracket as Apple hardware continues to be supported by Windows 10

To be fair, those same Apple machines from 2009 that are compatible with Sierra are also compatible with Windows 10 since they didn't put a gimped Intel atom chip in them.