I've said this before, though I don't know exactly where, so I feel justified in saying it again. If you want to know what it feels like to navigate everyday life with a physical disability, think about the last time you spent a day or more in air travel.
First of all, you can do it. It's not impossible. You can also have a good time doing it, and the payoff can be fantastic. However, it is tiring, there's lots of planning required, and if one small thing goes wrong or something isn't what you were assured it would be, it can quickly make the whole experience exponentially more frustrating and exhausting. Also, the central feature of the experience is that you are very much at the mercy of a glitchy system that you as an individual have almost no power to control in the moment.
That's what everyday errand-running is like for many if not most people with physical disabilities. Like I said, it's not unrelieved horror. There's no reason to feel sorry for us. But it is tiring and stressful, and we have to do a lot more delicate planning than most people do in their everyday lives. And when barriers crop up, like inaccessible buildings or no parking spaces, it's almost unbelievably draining ... just like air travel.