After the first group of young kids with no direction in their lives and the hippies that go to every festival, you've made maybe 100 million after you've paid performers, licensing, alcohol companies, sound stage crews, permits, etc.
Then the humanitarian problems with festivals. The amount of trash the supposed "good vibes" communities leave is absolutely atrocious, not to mention the number of ambulances that get called for panic attacks, ODs, physical injury, heat and exhaustion-related stroke, etc. is insane and WILL add up the longer a festival goes on as dehydration becomes a secondary issue.
Then you have to make sure each and every person has a satisfactory experience. Is it even fun after the first 100,000 people? Can you see the stage of your favorite performer? What if it's someone extremely popular and internationally known like Drake? Sounds like a good idea to pay him to perform until you realize how many people want to see Drake. Okay, now Drake is only coming if you provide him with extra security and a private lot for his team. That adds about 2 million to your costs. Are you gonna keep Drake to sell more tickets and play chicken with your profits?
After a while, cause one festival won't do. You'll need to make it happen for long periods of time or very often. You're going to need to pay so many people to fit the lot up to be what it needs to be. God willing, there isn't a flood or some other natural disaster and that's pretty much unavoidable these days.
And let's not forget the human element of organizing all of this, internationally, and nailing it. Despite every nation's individual laws (some of which nullify the whole "good vibe" culture as it were, Singapore will have you executed if you hit a joint), somehow making the diplomatic accomplishment of making it happen everywhere, all at once even though no country benefits from letting you do it.
This is the equivalent to doing the Olympics in every major city on the planet all at once and hiring contracted companies in each of those countries. Rio Olympics barely happened. It was a shitshow.
Also, festivals suck. They're a massive waste of Earth's resources 90% of the time.
You know what isn't? Oil and gas. It's what makes festivals even remotely possible. So I think the people pulling the strings are going to keep their current investments.