This makes it a deflationary currency: your holdings should** become worth more over time due to the limited supply: as more people enter the market there are few coins to buy due to more people holding them and due to those that are inaccessible due to lost keys.

So, in the early days, the people running Bitcoin miners originally earnt money both on the fees on the few transactions but also on minting new coins. The algorithm was designed such that "miners" would transition to earning revenue entirely on transaction fees once all the Bitcoin had been mined, by which point the economy should be up and running. In both cases this encourages them to actually run the proof-of-work nodes that provide the distributed ledger.

* assuming there is no successful change to the algorithm, which would require concensus by those running the nodes.

** this assumes people want to buy it – that a better investment vehicle has not materialised – and that Bitcoin has not been outlawed or had cripling taxes applied to it.

https://crypto.bi/deflationary/

There is a finite amount of Bitcoin, and the amount of Bitcoin that will be injected into the market is deterministic by algorithm.

(Note that there are several old bitcoin wallets with "dead" bitcoins that could one day suddenly become active, which I suspect would have the same effect as finding a new goldmine)