I'm wondeirng if the failure of the front CV axles is caused by split boots on the FWD/AWD cars or if it's the joint itself that fails due to excessive torque?

The reason why I ask is that after owning a few FWD cars and being stuck with stupid repair bills of replacing shafts due to seized CV joints or split boots, I had started applying liberal amounts of silicone spray once every few months on my current daily driver. Sure the cost of a new CV shaft is pretty reasonable, esp. if it's a reman unit, but why replace someting that you can get many years out of by simply maintaining it?

TIA