Parker Lewis eloquently articulates the significance of Bitcoin’s scarcity in his essay, "Bitcoin Obsoletes All Other Money."

This quote sums it up nicely.

"Recognize that there is nothing about a blockchain that guarantees a fixed supply, and bitcoin’s supply schedule is not credible because software dictates it be so.

Instead, 21 million is only credible because it is governed on a decentralized basis and by an ever increasing number of network participants.

21 million becomes a more credibly fixed number as more individuals participate in consensus, and it ultimately becomes a more reliable constant as each individual controls a smaller and smaller share of the network over time. As adoption increases, security and utility work in lock-step."