The government thinks everything accessible is readily achievable.
Not true. Often it may not be readily achievable to remove a barrier — especially in older structures. Let’s say a small business is located above ground. Installing an elevator would not, most likely, be readily achievable — and there may not be enough room to build a ramp — or the business may not be profitable enough to build a ramp. In these circumstances, the ADA would allow a business to simply provide curbside service to persons with disabilities.