I (think) I’m well known for dragging my years-per-computer out for a considerable amount of time - at least 4-7 years per machine, whether I buy them new or 2nd hand.
However I do accept that “Planned obsolescence” is ultimately a fact of consumer life. If Apple truly made their hardware - with free software updates - to last easily for a decade+, they would either go out of business due to lack of repeat sales, or need to charge a whole lot more up front for their wares.
Apple in particular within the electronics market (given their price) should be producing machines that last a long time - and we should be able to expect support for them for a reasonable time (counted in multiples of years). But whilst my comment above indicated an ire for Apple ceasing support for Machine X, this was based on my understanding (correct or otherwise?) that they were cutting machines off based purely on their CPU speeds, rather than actual ability. Something as arbitrary as that should not, imo, be a deciding factor. Specific actual hardware limitations are another matter.
(And to their credit, for example, I was running older Macs on newer OS’s in the not too distant past, that would have certain features disabled - like the transparent menu-bar etc. Presumably this could have been an option for Apple to simply not support the older machines that could not perform that task.)
(And… whilst we may say that Apple has “enough money” to throw into building software capable of continued support for older machines - any company that creates a business model that loses money is being reckless. The pin has to be pulled at some point…)
I do think that Apple have gone down a bad pathway with this whole glue era of hardware. To me that just reeks of “don’t even bother opening this up to for repairs - buy a new one instead”. I don’t think the price point warrants that attitude - they are after all still making one of the the world’s top line pro-sumer computers.