I have worked as a caregiver for a c2 quadraplegic, and have carefully considered this issue.

The problem is that disabilities are just that: disabling. As a result of a disability, there are actual limitations imposed on you, and those that care about you.

Sand can't be made crutch friendly. Natural areas can't be paved, and ramped to be made wheelchair friendly. Every hard surface in the world can't be padded to prevent mentally or emotionally challenged people from harming themselves by impacting them.

However, those that have suffered a disability can use tools to reduce the disability.

Consider for a moment the expense of retrofitting every beach, grassy swale, forest, and mountain so that EVERY disabled person can easily (as easily as possible) make use of it. Every public building, every stair, every alley, every street, every light post and sign.

The undertaking would cost more than the GDP of the entire world. It is not possible.

Consider then the cost of providing reasonable prosthetics and appropriate devices to the disabled so that they can use natural areas, stairs, streets and public buildings just like unimpaired folks can.

This latter expense is actually attainable, and aiming to do that will provide access to things modifying the whole world never will, such as the beach.

My friend, the quad, was able to run an aquarium business, despite not being able to physically do any of the work tending aquariums requires, because he hired helpers to do what he could not.

Crutches will never be of much use on sand, but tracked vehicles traverse sand easily. Rather than trying to pave the world, or extend boardwalks into every natural area in existence (forever ending actual natural areas as a result) consider how best to extend your capabilities beyond the limitations that have been imposed on you.

Just having a helper to carry you over the beach to the water would solve your particular problem. Having a tracked wheelchair enabled my friend to use natural areas, climb stairs, and he was even able to drive a vehicle by outfitting it with appropriate controls.

The world hasn't been disabled, and doesn't need to be paved. Your physical limitations can be overcome with appropriate application of technology, and you too can enjoy the beach, mountains, or any other place you may desire to go.

I hope you do not misinterpret my comment as without compassion. Rather consider the outcome I am advocating for: that your ability to use every place on the world be the result of your efforts, rather than giving up on those places that simply cannot, or will not, be modified so that EVERY disabled person can use them without better prothesis.