I have thought of scenarios bothering on the kind of policy or how its operation would begin to function once it reaches the said limit.

An interesting bitcoin fact is that the protocol for the bitcoin network was designed with a limit of 21 million coins in mind. As a result, cryptocurrency miners will eventually be unable to generate any new bitcoins.

Currently, there are 19.15 million bitcoins in circulation. This leaves a few million bitcoin to be mined, which is one of the reasons mining is still a popular activity.