Restaurants are typically swamped in the massive overhead of running an actual restaurant, and are not fully up to date with every latest bit of marketing toolkit.

Because they are not fully up to date on the latest digital marketing, you think it is justified that they be subject to what is effectively hoards of VC-backed extortionists - nice restaruant you got there... be a shame if some bad reviews got highlighted ... or here, we'll just hijack your phone listings and take care of delivery for you...

At least the mafiosi would occasionally eat at the restaurants on whom they were running protection rackets...

The Due diligence is required because of these new hordes of extortionists, not the restaurants (and no, it isn't all about your trivial convenience, OMG, they want you to call and don't have the latest web technology up for every function... nevermind the quality of the food, ambiance, or service, it's all about whether you can order it through an app, isn't it?)

sheesh