iPhone 12 Pro Max completely shattered in the back from half a foot drop.

I was putting my shoes on and had my phone in my hand. I was sitting while putting the shoes on, the phone wasn’t far from the ground definitely not more than a foot. I was tying my shoes when it dropped. It wasn’t throw or flew far out of my hand just fell on its back. I had a military grade otterbox case that was very expensive and well reviewed. This was the first time I ever dropped the phone I had preordered it the day it came out. The back completely shattered glass everywhere in the case. I had went to the Apple Store and Bestbuy to see what I could do about it. They told me it would cost a large amount to fix it. I know it was a long time ago but want to know if anyone has issues with their iPhones not being durable, if Apple has any plans to fix these issues in the future, or if there was anyway I could have gotten it repaired when it happened for not the full price.