When a cpu wears out enough to cause a heat issue, it would have been long dead. You'd get instability, errors, crashes, bsods long before any other symptoms. Even hitting 100c and being 100% a lot, your cpu isn't old enough to be running into issues. Unless you were 100% and hot multiple hours a day all these years.
I wasn't implying the cooler was bad. Most of the time it's just not mounted correctly. The easiest way to tell if it has proper contact is when you take off the cooler and see how the tim spread and how it was left behind.
I noticed your cpu isn't actually idling and nor is your gpu.
The hardware issue message could be from it thermal throttling so it's too broad of a message to tell if it is a sign of an issue.