Since when did Amazon & eBay accepted bitcoin?
Never. The same way as:
The total number of bitcoin is 21M and currently about 16.9M has been mined already.
Currently is about 17,3M.
I take OP trying to get merit but he will just end up in some peoples ignore list. Like mine. Apart from the imprecisions, he is not telling anything new: we all know that if demand increases, as there is the 21M cap, bitcoin price will rise.
Actually we don't really know how it all pans out. And on the other hand there's an argument that miners living off fees alone won't be enough to support their farms causing the smaller miners to drop off leaving just the largest ones making it more centralized.
Anyway, I encourage you guys to look up XMR's tail emission which is another take on when block rewards run out. But it's not just about having 'that something' for the miners when all the coins are mined, but striking that balance between the fees and (Monero's adaptive) block size.