The world already has infinite demand. As in people already want to own an infinite amount of things.
I would love to own a thousand mansions. If someone were to mind control me and make it so that I doubly want more mansions, that doesn't effect at all whether those mansions exist.
People "wanting" things doesn't make them exist, because society already wants an infinite amount of things!
Suppy is the act of creating things of value. Demand is just the method of DISTRIBUTING those things of value. But at the end of the day, what matters is creation.
Your restraunt example doesn't work, because imagine if I had a magic machine that could instantly create hamburgers for free. I could easily find people in the world who currently "demand" this food, for me to give it away to.
THAT is what it means to "increase supply". Creating things more efficiently for less resources is the exact same thing as having a magic machine that creates things for free.
Or in other words, if you haven't created more things using less resources, then you haven't actually increased supply.
Demand is just the method of distributing those finite amount of goods.