Everything works if you use User-Agent switcher extension. So they went through the trouble of making an "unsupported" page and redirecting you to that page instead of doing nothing
Not all Apple users are clueless.
A user can easily enable the developer tools if needed, same way I'm not a mechanic but can open the hood of my car.
Point is, this is not a binary choice. Between user and developer there are many people with varying skills that will use a user-agent switcher if needed.
Most people could do a bit under the hood of a car, but they simply don’t care.
It’s the same thing with computers. Most users are savvy. They just don’t care.