I've seen a couple of people sharing this ranking of vegan-friendly cities, which has also been picked up by some news sources, such as The Metro.
You wouldn't know the methodology from the news reports but, if you go to the original source, it seems to be based entirely on total
population divided by the number of vegan/veggie-only restaurants. It
takes no account of things like quality of restaurants or how
accommodating other restaurants are for vegans (which I'd say is pretty important in branding a city 'vegan-friendly').
labelling the table 'most vegan friendly cities' it doesn't even seem to
distinguish vegan from vegetarian. Theoretically, somewhere could top
this list based on having a lot of vegetarian restaurants without any vegan dishes.
I'm also curious as to how this ranking would compare with one of total restaurants per person. While I'd expect some places to have a higher proportion of vegan/vegetarian restaurants than others, it seems this methodology will simply favour places with more restaurants per head (assuming some will be vegetarian/vegan).
It's a pretty meaningless ranking I'd say.