There are all sorts of volunteer roles someone needs to do, from directing parking, to helping in the kitchen, to roaming around at 3am to see if anyone needs help, to working the first aid stand, and a hundred other things. I always sign up for at least a couple of shifts doing something, so feel like part of the "we" helping to put it on, but it's still something I go to as a participant to have fun.

As someone who does something similar, it’s easily both

In Australia these are known as "bush doofs" and are essentially community events - they're organised, run and attended by a group of people rather than an organisation.

You can't buy tickets to them, you have to know someone who's in the group chat for them. You can just turn up on the day if you know where the event is; they're always incredibly remote, usually on a patch of bush (forest) on someone's enormous farm or a national park, pitch a tent, join in, help out where you can. Security is "if you act like a dickhead you'll be asked politely to leave by a bunch of people". There's no financial contribution, except sometimes a hat is passed around if someone had to pay for equipment hire or similar. You can buy drugs there, but only if you know the person you're buying from; usually better to sort yourself out before you go, there won't be anyone advertising anything for sale at the doof.

Those two things are not mutually exclusive.

The best festivals are co-creative experiences.