That said, it seems like for society to work as it does we need people to take some level of responsibility over their action and inaction related to account security. If I live in the world you describe all online services will be forced to make you upload a photo ID for each purchase to confirm it is you.
I'd find a jury unwilling to believe that a similar real life scenario would raise no flags. It's only a flag raiser because tech companies have automated away all human interaction with billing. Imagine someone claiming to be bob, who regularly shops at the grocery store for 100 dollars a week, now wants to come in and spend, say, 10,000 dollars, on credit. This would be a red flag to any proprietor. Now imagine that proprietor going after bob, who was not there, and claim he is responsible.
The attitude of "provider should eat the cost" is ripe for abuse. I can set up some expensive GPU instances to train my GPT4 clone (millions worth of compute) than -after getting my models- claim I was "hacked" and refuse to pay my bill. Or maybe -more benign- have some buyer remorse after setting up a public instance for people to test out my new AI product then get scared when it gets the HN "hug of death" and my bill skyrockets.