There are practical limits to the supply of gold. There is no limit to the supply of crypto currency. That can be created out of thin air by anyone at any time.
the whole point of bitcoin — whether or not you believe it has a future —is that it allows for (and has) scarcity in a digital environment in which double-spending/scarcity were previously hard to enforce without an intermediary.
there are only ever going to be 21 million bitcoin. there is a limit :)