A great many potential escape room customers are not looking specifically for escape rooms, they're looking for something fun to do in the area. So, again, no ability to advertise would be a gigantic advantage to established incumbents in the "something fun to do with friends" category of businesses.
What city doesn't have brochures of fun things to do, community newspapers where new things like this can be announced or meetup groups for people that like activities like this? There are a lot of ways potential customers can actively find you without manipulating random people who weren't looking.
Maybe technically, and mostly because of how they're typically implemented. I'd call providing brochures to people that explicitly request them information not advertising.
So you start Apple Maps and look for fun to do. You know the data in Apple Maps does not contain spam. Even the local tourist center might have information available. Or you ask around on an escape room subreddit or escape room community forum.
