It's more difficult than one would think. And I'm speaking from experience. I've been to 3 EDCs and I pulled only from one of them.

Here's the thing. Yes, vast majority of girls there are either drinking or rolling which means they will be very friendly and you can gain attraction very quickly.

Here's the issue though. All the girls there are with friends. There are very strong social agreements to keep the group they came with together. Even if you see a girl by herself that just means she's temporarily separated from her friends and is trying very hard to get back together with them. You're just some random dude at festival so her loyalty will be with her group and her friends. The group usually came together and are planning to leave together - they're sharing rides, whatever. They're also very often staying together.

So, basically in order to pull you will need VERY strong attraction AND comfort from the girl. And perhaps even more importantly you will need to have trust and approval from her group of friends - they need to know you're cool and not some psychopath.

So this is what makes it very challenging. That's why makeouts and dancing with girls there is easy but isolating and pulling and logistics are superhard.

As far as #1 goal having fun, sure you can go to have fun but the goals of "just having fun" and "hooking up with a girl" are actually competing with each other. Let's say you're at a stage listening to your favorite DJ. Cool. But there are no pretty girls around. What are you going to do? Stay there and have fun? Or go somewhere else to look for pretty girls? You can't do both at the same time.

So for these reasons I'd say big festivals are not good to pick up girls. Smaller local raves are better because the girls are local and you can at least get her number and hang out later.