when greece switched to using the euro it benefited greatly it switched from a low value currency to a high value currency that being said if greece had its own currency it could print as much as it liked until it stimulated economic growth in addition having a weaker currency would attract investment including an increase in exports and tourism the downside is that printing too much money would cause inflation 
despite any benefits of having its own currency greece benefits from being part of the eurozone it has a strong currency it receives aid packages and using a powerful currency makes it safer and more efficient for companies to do business greece benefits from stable financial markets because of using the euro which generates investments and trade using the euro does come with rigid rules that often don t benefit less wealthy countries like greece while greatly benefiting wealthier ones like germany 