9 times out of 10, it's the motherboard, NOT the CPU.
Intel and AMD do a very good job with quality control.
I've repaired of thousands of desktop systems and can only blame the CPU in a couple of instances in heavily modified PCs where the cooling system failed.
Hard ware problems always seem to relate to heat somehow.
The number one hardware failure is the power supply. Many times they do not fail gracefully and fry something else.
Number two- motherboards. As everything is built into the motherboard these days, any failure in the most complex part of the system is fatal.
Number 3- hard drives. They are so much better now than they were just a few years ago.
Number 4- RAM very rarely goes bad unless its mishandled.
Way down at the bottom of the list are CPU chips. They just don't fail unless you cook them.