Ebay, amazon and other companies like them will never accept bitcoin. The main reason:

1) There are a lot of scammers in the bitcoin sphere and we know that already. The issue is that is someone is scammed on eBay, for ex, Tony buys a laptop from George. George gets the $ on paypal immediately, but never ships the laptop. After a week or 2, Tony makes a report on ebay, which then takes the $ in George's paypal account to give back to Tony, while also suspending George's account. However if someone were to get scammed after paying Bitcoin, there is nothing eBay could do to get their bitcoins back, as bitcoin is nonrefundable(which is a huge issue when it comes to adoption). No one wants to know the money they spent and got scammed from is gone forever, with nothing they could do to get it back.

Now, some of you may say, "Well you can use an escrow system to accept Bitcoin, you know like they do on drug markets on the darknet". That may work on smaller mutlivendor marketplaces, but I'm pretty sure sites as large as eBay and Amazon won't want to deal with the constant reports of "I didn't get this package and my bitcoins are stuck in escrow, can you help me?" etc etc that come with an escrow system, as well as the fear of getting hacked.

And that's besides Bitcoin's extreme volatility and slow confirmation times, etc