To what extent are the principles of democracy developed in Athens under Pericles suitable for modern times?

In Athens, any citizen, regardless of wealth, nobility and occupation, could take part in elections. All power belonged to the demos (people). Elections were held. Every citizen could make a proposal in the Assembly. These principles are perfectly suitable for modernity, because it is not without reason that Athens was the most powerful state in Greece and its cultural center under Pericles.