So instead, I want you to imagine the sea or a very large bay, the most wide open space available, then I want you to imagine a ferry that can carry 500 people, big yes but there's still plenty of sea and its reasonably tranquil.
Now imagine 500 people on jet skis roaring around, then imagine that the jet skis and ferry are all trying to get somewhere different but that's relatively the same, perhaps commuting between the different sides of the bay.
If I was mayor I would put a stop to 500 jet skis and say look you have to use the ferry, people on jet skis keep colliding with each other, the noise is horrendous for people on the beach and makes swimming dangerous, and it's also wildly power inefficient when you step back - that's even if we ignore the pollution! 1000 spots to store a 500 jet skis on both sides of the bay is perhaps even worse!
If you can make a sea packed and grid locked with just 500 just imagine what it does to a city with thousands, hundreds of thousands, if you then turned to me and said the jet skis drive themselves! I would still think most people should be taking the ferry and there's a upper limit to sustainable jet ski use.