Inspired by Marco Bonelli's answer.
Answer:
SE reputation
Explanation:
A wave of the hand is all it takes to dismiss,
Deleting the account also deletes all your reputation (and reputation you gave to others with votes)
But when it gets started, it's greater than this!
When you use the system well, your reputation will start to grow.
A bringer of gifts. A destroyer of food.
Reputation gives you badges, the food I think is just for the sake of the rhyme.
It helps win the race. It ruins the mood.
You can have the greatest reputation, but if you start to lose it...
See it, then not... or the other way 'round?
Upvote, then downote. Correct answer, then revoked.
Answer this wrong and it's still most likely found.
Also if this is wrong, I hope to get some upvotes :)
Puzzlingly meta, you'll answer with glee,
Upvotes and downvotes in meta sites of SE doesn't change your reputation.
So tell me, dear riddlers, what the heck can it be?