I have a large ziploc freezer bag completely full of broken 12spd XTR and XT derailleurs from the last 24 months of riding. I also have a smaller bag of broken or worn XO1 and GX derailleurs. I'm on my 3rd AXS derailleur as well.
Some of the failures are bad luck: a grapefruit sized rock jumping up, or a errant stick flicked by the front tire. Many of the failures are design or materials issues. The XTR carbon cages come to mind, and there are many more issues well documented online with both brands.
None of these failures were poor line choices.
The 24 month period preceeding the one above? Not a single derailleur failure.
Shout out to my first AXS derailleur. It went to hell and back, and at the end of its life it was unrecognizable yet still shifted with absolute precision. I'm guessing it outlasted what would have otherwise been 4 mechanical derailleurs.