Generally at low-moderate restaurants (especially ethnic) the problem is "getting staff to pay attention", at slightly better restaurants my problem is "JFC leave me alone, we're trying to have a confidential conversation". At great restaurants (e.g. Alexander's Steakhouse in SF/Cupertino) they are good at figuring out exactly when to bug you.

Tech could certainly help the lower end restaurants up their game, even if not as relevant on the high end. And on the high end, I could see some kind of CRM making a lot of sense, if they don't do it already -- knowing my preferences on table/etc. is easy if there's only one maitre 'd and location, but if you've got a few locations, tech would help share information.