The concept of 21 million bitcoins supply cap has pushed me to learn and understand more about economics. The law of scarcity, supply, demand and the concept of money.
Only scarcity does not make a high price for Bitcoin. You must learn more to know why Bitcoin is favorite than altcoins, Bitcoin forks and why with same total supplies like Bitcoin, Bitcoin Forks don't have same price as Bitcoin and many of them are dead coins.
Some forks and you can check like 5 forks to see their prices as well as check their network hashrates.
https://blog.bitmex.com/44-bitcoin-fork-coins/