not just that, people keeping to older OS’s will actively avoid converting to new hardware sales..

I did not upgrade my laptop because it would come with the latest OS- I am not alone.

The other side of it is forced obsolescence where new OS makes your existing hardware slower. So I wouldn't upgrade my phone beyond iOS18.x purely for performance reasons but if there's a killer feature in a new iPhone I would still consider buying it because its hardware was built to handle the new effects and extra ram it needs.