As Mr. Perma noted, treif chains don’t do well in North America.
The reason is this: The value of chain branding is that people can expect the same product as lat time. Kosher restaurants all have their own reputation anyway, so nothing is gained from the branding. After that, there’s just no reason to tie yourself down to the Mcdonalds way of preparing and wrapping a burger and their menu, and pricing, etc, etc.