The word monopoly has lost all meaning online, it seems to just be synonymous now with 'successful business'.

You can cut Amazon out of your life tomorrow if you wanted. You could do it almost entirely with just Walmart.com if you wanted a dropin replacement.

If you only have one internet provider in your area, that's a monopoly, the cost of switching is essentially 'start an ISP'. Having to type in walmart.com does not make Amazon a monopoly.