The key word is professional. A good restaurant website begins with taking good photos of the premises and the food. AI won't come around to your business and take professional photos.
There's a lot of bits and pieces to a website for bookings, content management, menu updates, etc.
HTML templates and themes have been around for a long time. AI can basically spit out those templates and themes, which is great. But there's still a lot to do before you get to www.fancy-dining.com.