The benefit of an inclusive society is that it becomes future proofed. One day many people will need greater access too.

The cartoon at the bottom is an updated version of the more well-known original, and a light-hearted take on an inability to use stairs.
The thing is that when you have mobility impairments, or are with someone who has problems getting around, you are dictated to about where you can and cannot go by the environment around you.
The benefits of greater accessibility are beginning to be widely recognised.
They of course create a more inclusive society in which people with mobility impairments can be a part, along with everyone they know. And then, there is also the secondary benefit in that others can also benefit (for example, parents with prams).
The most important knock-on effect is that all these increases in accessibility future proof our society, meaning that we will all benefit at some stage in our lives.
Decreased mobility is not something that anyone welcomes but it is going to become ever more common as we get older and medical advances keep us going for longer.