Over 17 million Bitcoins have now been mined. That means there are only 4 million more that will ever be mined.
As more people try to mine them, they get harder to mine. As the price of Bitcoin goes up, more people will try to mine them. Regardless of how difficult they are to mine, a block will be mined roughly every 10 minutes (as that is coded into the Bitcoin algorithm). However, also programed is that the reward will half every 210,000 blocks. That means as time goes on, less and less Bitcoins will be mined. The last coin will be mined around year 2140.
After the last coin has been mined, miners will the rely on transaction fees (if another mechanism isn’t put in place via consensus). That opens up a can of worms, but that is a distant future can of worms.
For now, it is a game of getting one’s hands on the limited supply of Bitcoin’s in circulation and the newly mined Bitcoins… because once the last 4 million are mined, the only way to get Satoshis will be through trading, offering goods and services, and transaction fees.
Although scarcity poses some issues, it is also one of the factors that leads to higher and higher prices. Consider, as scarce as Bitcoins are, the circulating supply on the exchanges is even more scarce. If and when people become unwilling to part with their coins, we could start seeing rapid increases in valuations like we saw on the run-up to $20k (that wasn’t a matter of true scarcity alone, it was a mix of pumping and rapidly increasing demand in a short feedback loop… but of course, that is very likely to happen again).
There is no doubt crypto will be volatile, but scarcity, demand, and a little pumping could realistically drive prices through the roof in the coming days, weeks, months, or years… and that is an exciting prospect. If it weren’t for scarcity in the fixed supply and circulating supply, that would likely not be the case.