Bitcoin's limited supply (ie. scarcity) is not the reason for bitcoin's success and the massive potential for growth it has, it is just the cherry on top. The real reason for bitcoins potential is the unique utility it provides as the only available decentralized currency that can work globally in the safest way possible.

If it were any other way then thousands of altcoins that have limited supply would have also succeeded, some of which should have surpassed bitcoin since they are much scarcer than bitcoin (eg. 42 coin that has a supply of 42 coins!).