Most decent manufactures of carbon enduro bikes make them with Alu rear ends because they are more resistant to rock strikes and simply dent.
LOL really? They do on the cheap end bikes as it’s cheaper and you still get the front triangle as Carbon.
Bit of both in reality though.
I remember reading the Yeti ASR5c (?) review in Dirt where they admitted they had crashed and cracked the chainstay during the test, and Yeti told them it wouldn’t have been warrantied for a punter.
I’d probably be happier with carbon front/alu rear as a real-life compromise.