IMO, it wouldn't limit economic growth or affect credit creation if Bitcoin is the only global currency. Imagine when 0.001 is worth about $10,000 or more; then you wouldn't need 1 bitcoin, whose price is still $28,000 today. Probably, Bitcoin would have more value and the price would be high, and private individuals who have enough Bitcoin would have the advantage of lending some fraction of their Bitcoin to different business individuals. If the price of bitcoin is so high, and with a supply that is limited and can also contribute to the high value, then people can still collect loans in which a little fraction means a huge amount that could settle the desired project it intend to be used for.