I feel a little dumb for having to ask this and I think it shows the society we've grown up in to our detriment.

How does a business grow in the sort of parallel economy we envision? At least at the beginning, we as individuals only have so many fiat notes with which to purchase items and sell for Monero in the parallel economy before we run out of fiat. We obviously can't take fiat loans because our business completely destroys fiat with no hope of returning. We cannot borrow in Monero because we still would not have fiat to purchase more items with.