[SERIOUS] Why haven't the big eCommerce sites adopted crypto yet?

I think if Amazon, Google, or Apple decided to accept crypto payments, the market would explode, and we'd start to see a true crypto economy much more loosely coupled to fiat than right now. I'm surprised one of them hasn't made the jump yet. Not only that, but whoever is first to market, will see the greatest gains.

My wild guess is it's the accounting that's holding them up, how can a company account for its money with an asset that's so volatile? To me, it seems like the earliest solution would be some kind of smart contract that automatically swaps the volatile coin for a stablecoin. If the price is held for something like 15 minutes so the user has time to browse, sometimes the company would be getting an above-market-value rate, sometimes it would get below, but should even out. Is something like this what's holding them up?