Design drives sales online. Entirely. If brick and mortar stores had to design their entire storefront and display area around wheelchair accessibility first to the detriment of 5-10% or more of recurring revenue we'd instantly have a small city worth of lobbyists to reverse it.
In the US, the ADA does indeed mandate many things (reserved parking spaces, door widths, ramps/elevators, etc.). Though to continue the analogy, I think we'd need to extend it to how the merchandise itself is displayed/marketed—for example, requiring all products to be accessible by someone in a wheelchair, braille on all packaging, etc.
Notice the usage of "Undue Burden" from the official ADA documentation: "The rules are also flexible for communicating effectively with customers who are blind or have low vision. A sales clerk can find items and read their labels..."
