Is a chauffeur really different from Uber Black in Miami Beach?

Yes, in three ways that matter and one that does not. The one that does not is the car. A black SUV is a black SUV.

What differs is who is driving, whether it is the same person twice, and what happens when something goes wrong. A chauffeur is assigned to you ahead of time, not matched at the kerb. On a longer stay it is the same person each day, so by the third morning nobody is repeating the address. And when a flight slips or a dinner runs long, there is a number that answers rather than a queue.

The price also behaves differently. It is agreed before the car moves and it does not change because it started raining in Miami Beach or because everyone left the same event at once.

If the trip is short, cheap and in the middle of the day, an app is fine and nobody should pretend otherwise. The case for a chauffeur is the airport at six in the morning, the dinner that matters, and the week where the same car should simply be there.