Yes I think it's enough
Because each Bitcoin can be divided into 100,000,000 units Satoshis sats. 1BTC= 100,000,000 sats, so this means that there are effectively 2.1 quadrillion Satoshis in total
So even if Bitcoin gets to a very skyhigh price, there will be no need to hold a whole Bitcoin to your self. We can just make transactions and save in tiny fractions. so that's it, if Bitcoin had an unlimited supply like regular Money, it would lose purchasing power and value over time
I believe this is one of the major reasons why Satoshi invented Bitcoin with a limited supply so that it would not devalue over time. However, the limited supply calls for every sat's continued increase in demand and value as the adoption continues to increase globally. As time goes on, every fraction of a satoshi gets more value as the demand keeps increasing, so 21 million satoshi is enough to sustain the world as the value keeps appreciating over time.