Not infinite. Converts organized matter into other organized matter. You could put a person in one side and pop a cheeseburger out the other but once the mass of the person is gone you aren't getting anymore cheeseburgers.
I think the biggest thing they needed, in addition to realizing how bad they were fucking up, was a massive reduction in population to give the earth a chance to rebound while humans got their shit together. I think we're actually ahead of the technology curve presented in Star Trek history, and our ethics are tracking a little better, since we didn't already have a massive eugenics project. So if it can be done, we could do it if we get our shit together. Hopefully it doesn't take a eugenics war, and a world war to wake us up.