Rockstar Games are gearing up to add age verification methods to GTA Online. Following the UK's implementation of the Online Safety Act services such as Reddit and Xbox and have to verify the age of its users to make sure they are over 18 for certain content.
So, I loose no functionality when I pirate it?
Wrong. You “lose” the age verification feature.
You might not be able to connect to FiveM servers, which IMO is a major loss. FiveM is the real GTA V.