Well I think the opening Post is pretty misleading. While old PCs depending on their configuration can be made to run Windows 11 it's neither endorsed, nor supported (8th Gen or newer Intel CPUs and newer as well as TPM2 required). In that regard it's not to different from macOS which almost supports all 2018 and newer Macs, which just coincides with 8th generation Intel CPUs. While the TPM2 enabled secure boot chain on the Mac side is realised via the T2 chip, which among secure boot has other benefits as well. And even considering, that these restrictions can be circumvented on windows 11, you shouldn't forgetting, that the same is true for macOS (OCLP and similar) as well.
However what Macs' longevity is about is, Software support as well as resale value and overall reliability. Even new Mac software (apart from games) usually support some macOS release prior the current one, so there is mostly relatively little friction regarding software support. This is mostly also comparable to windows of course. Macs resale value shouldn't be underestimated as even 10 year old machines still fetch at least 10% of their original value, and additionally almost any repair part still can be found. Also even low tier Macs from almost any era represent many times mid to high tier CPU components (mostly i5 or better CPUs) and other components such as screens and chassis where usually above average for their time. Not to mentions their build quality. All of this results into their reliability.
In our family just last year we took my old 13" 2012 MacBook Pro out of service, though anecdotally not because it stopped working (still lasted around 1,5h with its original battery), but because of a finance tool running in bootcamp, windows which refused to work on this old machine. Privately it was used on macOS. It ended up being replaced with a 2018 Mac mini (i5), which after selling this old MacBook just cost around 80€ more.
So while the MacBook was already slow (and the SSD upgrade it received sometime during its lifespan, it was fine for the weekly use it experienced, which was mostly writing and printing letters, sending emails, sorting and managing photos, doing some light browsing like online banking and making video calls. The finance software was mostly run in a Windows VM till its update didn't even let it run in BootCamp.
As I'm the go2 IT-guy in my family I also manage some windows machines. And in my experience even an 2015 i3 notebook is borderline unusable after at most half a year of usage after a clean install. Already moved some people over to linux which works far better on this old hardware. (I found ZorinOS to be the best "no fuzz" and tinker free distro for Windows people as it's visually basically a drop in replacement and being based on ubuntu mostly just works).
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@iHorseHead: Regarding your references to 2017 era Macs: While you apparently have good memories at least the Apple laptops were objectively the worst model lines they had in a long while. Bad keyboards. Lots of overheating/throttling issues. Current Macs are insanely powerful and well specced for the price - just this summer there finally appears to be some competition and catching up in progress, though within the next three months updates are due.
Regarding your remarks regarding security: I wonder what makes you think that Windows is more secure? They are mostly not because they can't be. Will Windows Defender is usually quick and you don't have to much issues with security if you act cautiously if you infect your PC basically anything can happen. That's not true for Macs as the OS cannot be altered unless explicitly allowed. This cannot be done from within the OS. Also currently not even UEFI Secure Boot can guaranty boot and hardware security as it's fundamentally broken, while on the Mac side there aren't any known exploits whatsoever.
And last I want to refer to your iPhone comments. While "ordinary" iPhones for the last few years were a generation behind in terms of CPUs compared to the Pro Models this is almost certain to change this years. Also those "old" CPUs mostly run circles around even the lastest CPUs the Android world has to offer. Maybe not always in multicore performance, though hardly any mobile software uses more than two cores at once so any number of additional cores should be plenty on a phone.
And I don't really get why you complain about new iOS18 features, even though they have been available for android years earlier. Just feel happy you get them? Also regarding AI features it's not even comparable, especially if you value privacy. If you consider privacy as being a part of security, which is a argument which can well be made, neither Windows nor Android come even close.
In the end all comes together as a choice of preference, but I don't think the points you mentioned are valid to draw your conclusions.
