Plenty of eateries don’t have vegan options

Maybe you are thinking of processed vegan food, like a vegan nugget or hamburger. That is completely unnecessary. beans, lentils, chickpeas, seaweed, grains, rice, vegetables, nuts… those are widely available and enough for a healthy diet.

For the rest I agree, it’s easier to convince an omnivore to go vegetarian than vegan. But that has to do with their will, not with actual physical limitations.