That's not an option for a lot of people. For example, the vast majority of physical shoe stores simply don't carry my size. There is literally only a handful of stores in my country I could go to - and I don't even have an incredibly unusual size!

Physical stores increasingly cater to the average. They would rather stock 20 different items in 5 sizes than 10 different items in 10 sizes. All of the long-tail stuff is only available online, so you are forced to buy online.