Even in Alaska fly fishing destinations can seem busy at times. That said, it is all relative. Some feel that a beat system can help spread people out and have a schedule of areas for people to fish. This type of approach can be embraced by some and criticized by others.
There are many rivers around the world that operate on beat systems. I imagine there are a few different ways to scale a beat system to a specific water body.
One way a beat system can be scaled is to use fairly simple math. If a river has 700 Salmon caught over a season it allows 700 rod days a year. The season for sea run fish species is typically 90 days so a river with 700 salmon caught every year would allow 7 rods to fish the river on a daily bases.
This makes the fishing in some areas of the world more exclusive and it also helps both protect the anglers right to privacy while fishing as well as protecting the stocks from too much pressure.
Fishing a 15 mile area that has 3 beats, each rod then has 5 miles of fishing area.
I can see arguments pro and con for a beat system. At a glance it seems more enticing to me to fish a river with less people and fewer boats running around looking for a place to fish. Similarly, would you rather wait in a line with 10 people or 100 people….