This is all wrong
Taking all this stuff is unnecessary and totally against the spirit of things.
The more stuff like this you take, the more likely it is to get nicked (or lost). Personally, beyond tent, sleeping bag, clothes, and army boots (important!) the only other gadgets i ever took were a plastic cup and plenty of boxes of wine. Frankly, if you can't enjoy yourself with these things and the good company and music, then you really shouldn't be going. And if you end up at a Glastonbury mudbath like I once did, you will be very glad if you follow my advice instead.
Being at a festival should not involve worrying about charging your devices or posting on social media or dressing stylishly, but rather about getting away from all these things for a few days - if this makes me a sad old fart then so be it, but were I to risk enduring a festival again I would still do it the same way.Though I will concede that this wouldn't have made for an interesting article on a technology website.