In the US, restaurants absolutely do hire more people than they require. Employees are paid on tips. Add as many $2.13/hr servers as you can. Hire hire hire. Never stop hiring. You'll be sloughing off people constantly because they aren't making enough money, so you have to keep hiring ever more aggressively to feed the beast. But you'll have 5 people to run every plate of food, bus every table, all that stuff.

Of course, one really competent server is as good as 5 of the ones being churned, but it's too hard to get and hold onto one competent server, so better 5 incompetent ones.

This is why the only way to judge how well-managed your favorite bar/restaurant is to look at their (non-family) staff turnover. If the same cadre works there for multiple years, you know it's top-notch. If there's a new cast every few months, you know its management is a shit parade.

That doesn't really fit with the extremely popular model of having a bunch of people scrambling for hours and never getting more than 30.