It says that there will only ever be 21 million Bitcoin and the current BTC supply is almost at 19,094,150. What happens when its limit reached? will BTC price goes up instantly due to scarcity? is it the doom for Bitcoin since there is no room to mine? or maybe it will likely never reach 21 million?
It will probably never reach it as scarcity is not the only factor why people invest. Utility is a big factor and if BTC loses it's use factor to other coins, it might fall out of favor. That's not a bad thing nor is it something unexpected, but as it get's replaced, people might loose interest.