if you want to live with a 20 year old OS then feel free to revert to say Win3.1. Good luck on getting any recent software to run on it. You can only keep patching in new technology for so long before it all falls over under the weight of hacks to get stuff working.
I would suggest that most people who buy a PC simply want it to continue doing what they bought it for, until it dies from physical failure. For the great majority , adapting to new technology is of neglible interest, and I doubt that anyone buys a computer to run a program which will be developed in ten years time.
All they need is that the PC keep running the hardware that they originally purchased.
Even so I am amazed at the inability of developers to make software reasonably compatible from one generation to the next.
And your support costs only fall to zero after 10 years if your product is frozen.
As far as I am aware XP is frozen.
Let me guess, it was something niche, specialist and of limited scope. Some sort of embedded system like an FMS ?
Nothing niche or specialist. Much like the stuff that goes into Microsoft operating systems.
I still maintain that you are very much still wearing rose tinted spectacles if you seriously think a modern Operating System, or modern general PC software should last 20 years !
I can think of no good reason that a modern operating system should not last 20 years. The only impediment in principle would appear to be the fact that it does not suit software suppliers.
On occasions an OS may be superseded by events that come as a surprise to the supplier. The appearance of viruses, etc.on a massive scale is clearly such an event, but such a surprise is hardly a normal occurrence.
The vast majority of large buyers operate on a 3 to 5 year lifecycle.
Which might be one reason why people manage to spend extraordinary amounts of money on systems which never get to work. If a hardware supplier had told me that they were working on that sort of lifecycle the conversation would not have continued for much longer, and that was when electronic equipment was far less reliable than it is today.
Quite frankly, talking about 20 years for generic office (or home) systems is simply ludicrous. I think you very well know that.
Ludricrous to who ? The supplier or the customer.