I feel the same about "extra effort". When I lived in New York City, many vegetarian restaurants would go out of their way to get kosher and halal certified (by conservative clerics). The owners would prominantly display the certificate at the entrance, plus the menu would share the same information. In my view it was two things: (1) virtue signalling (fine by me), and (2) appeal to a more customers who might not "naturally" be vegetarian. I knew many Orthodox Jews at my office. If their favourite Jewish Kosher lunch/dinner place was closed, they would check for kosher veg options.