They control the number of people on the trails only if you are in the group that is backpacking as in staying at the camps within the canyon. What is not controlled is the number of people "day hiking" rim-to-rim or even rim-to-rim-to-rim. And many of these people are more interested in filming the trip than paying attention to what is around them. I don't know how many times we, backpacking, were almost run over by these individuals. They have actually had to reduce the number of people staying at Bright Angle camp by 50% due to over flowing sewage treatment plant due to the large number of "day" hikers stopping to use the restrooms on their way through the canyon or so we were told by a ranger during a ranger program. Because the rim-to-rim in a day hikers/runners aren't using a campsite, they don't need a permit so anyone who wants to try can anytime they want.
The upper mile of the Bright Angle trail was also so overrun with day hikers only exploring the upper reaches of the trail that we could barely get up. Most don't bother reading the sign that says hikers coming up have right of way. I actually stood face to face with hikers that were expecting me and my big backpack to get out of their way on the narrow trail so they could walk down the middle with their phone and bottle of water in their hands. I was not the only backpacker telling people that hikers going up had right of way. There were two other groups doing the same hike as Brian and I that were having the same problems and doing the same thing.
Grand Canyon was totally overrun with people while we were there. There was no place to park (the blue village bus was not running due to COVID cleaning requirements) and hiking along the rim trail was more like walking in line. It has become more of a tourist attraction than a National Park. It is still beautiful but there is little communing with nature. Just way too many people and kids running everywhere. So many were climbing on the rocks on the edge of the canyon it's a wonder that none fell in.
We did see four California Condors at a rest stop on the Trans-Canyon Shuttle!
Found Myself Outside