Small local retailers are what makes a town a town. If everyone just shops online, there is no local personality. People need to shop at small local businesses in order to have a place they still call...
The problem's at its worst with the likes of Amazon. They're able to pay such a low effective tax rate that money is massively draining away from local communities and economies. They use nations' infrastructure to conduct their business without paying for it. I don't even really blame them for it. They're making the most of a car crash international tax system.