As has been mentioned TPM is a necessary condition for upgrading to Win11.
However, it is not a sufficient one, and CPU age seems to be a somewhat hit or miss factor.
I was unsurprised that my ~6 year old laptop with a 9 year old AMD A8 CPU wasn't going to make the cut, but disappointed that my 2 year old laptop with a 3 year old AMD Ryzen 2500u does not. It has TPM 2.0, which is enabled (I checked the BIOS), but for some reason Windows doesn't want to recognize it.
I checked for the AMD PSP fTPM support in the BIOS mentioned in the Bleeping Computer article William Parcher so helpfully linked to (Thanks, WP

), but could not find such a setting. I suspect this may have something to do with the problem.
The CPU in question is not included on MS's list of compatible CPUs. This is also probably a contributing factor. Why it is not is a puzzle, since it seems to satisfy the horsepower,speed, and bandwidth requirements.
Here's the the thing. There are
a whole lot of computers out there, desktop and laptop and tablet, which aren't going to make the cut. It isn't just a handful of older models.
And MS has announced the End Of Life for Win 10 to be 2025. So in four years none of those computers are going to get any security updates or support.
My older laptop has a 17" screen, which means it is my goto device for most sustained reading. It has been chugging along so well that I swapped out the original HDD for an SSD, and have been quite pleased with the improvement, especially when booting up.
My other laptop is a 15+" which does very well, much faster than her big sister, and barring blow-ups I had hoped for it to hang in there as well.
We aren't talking phones here, people. These gizmos are expensive, and now MS is essentially deciding by fiat that a huge chunk of the computer using public is going to have to buy new machines in four years or suffer the consequences.
Not a pretty look.
But I guess we know now why Win 10 wasn't the last version after all.