Its year is 2024 and approximately 1.5 million bitcoins are left. What can we predict and prepare for until 2140 when bitcoin will be mined? Could we increase the amount of bitcoin, or will it just end? What will happen second before and after Bitcoin reaches its limit?
Fixed supply of Bitcoin is perfectly fine. There's no need to increase it, as Bitcoin is divisible into Satoshis, so there is likely to be enough of it for everyone who'd want it at that point. When the demand is high and the supply is low, it drives the price up. So the scarcity can mean that Bitcoin would get way more valuable, but it doesn't mean that it would be the end of life for Bitcoin.
Also, let's not forget that it's highly unlikely that any of us will be there to witness those events, and that the world is changing so fast that it's impossible to predict whether Bitcoin will be relevant to humanity in 2140.