they couldnt care less if your item goes missing.
If your item goes missing your issue is with the courier you chose, not eBay.
I’ve has eBay remove my negative feedback against a buyer when the buyer refused to leave me feedback for my confirmed prompt payment until I had left them positive feedback. Obviously that is blackmail, but eBay sided with the buyer when the buyer complained about my 100% honest neutral (i.e. neither good or bad) feedback.
So eBay certainly does not side with sellers, especially when those sellers put lots of business eBay’s way. Just check the amount of fake and/or illegal and/or misrepresented goods on eBay by ‘Power Sellers’.