it's not just service, the food is also elevated. experience and setting are big. though it is somewhat unspoken, everyone knows that one star restaurants are somewhat designated for inventiveness, creativity and quality of the food almost in isolation with little regard for the service/setting. hell, i think an argument could be made that the con todo taco truck could at least get some consideration. but to achieve 2 to 3, the techniques require significantly greater elevation and precision in their eyes.
as to the service, it is a lot of both tangible and intangible things stemming from professional levels of service and training. it's a bit of a you know it when you see it thing. the "forks" episode of the show "the bear" wouldn't be the worst introduction into what i mean.
the recruiting thread did cheese puns for nearly 30 pages and the coaching search thread did burger ratings for like ten days. but point taken, i'll hit eject with saying that imo, quality and diversity of restaurant offerings in austin is one of the few things that is not the subject of a wtf is wrong with the city topic.