The conch shell is representative of authority in the early days on the island. It allows Ralph (with Piggy's help) to create order and there is an attempt to create a mini home environment - as best they could. The shell becomes more than just a symbol and gives legitimacy to the person speaking - thus inferring democracy.
We can use this to call the others. Have a meeting. They’ll come when they hear us..
In modern society, freedom of speech and a right to elect leaders is crucial to sound governance and fairness . The conch is the closest the boys can come to this realization. It shows a maturity on Piggy's side - which rubs off on Ralph, a natural leader.
The conch brings the boys together and creates a common purpose- even if only temporarily - much like co-operation between countries is necessary in a world of imports and exports and transfer of skills and so on.
The boys appear naturally drawn to Ralph’s stillness, attractiveness, and the fact that he possesses the conch that summoned them.
Those who speak through the conch are expected to show respect and those listening must infer respect to the one speaking. This is relevant in the modern day as there are so many ideas and so many possibilities that society demands to be heard.
What is also important is how the conch loses its efficacy becoming
clear, almost translucent.
Ineffectual government would have the same problem and in democracies governments change and new leaders are elected.
We refer to ourselves as supporters of various 'parties' such as democrats, republicans, independents, conservatives, liberal and so on and the conch is representative of the boys' style of leadership. It is relevant that the conch is destroyed at the end when Ralph's leadership is no longer effective, ensured or even in existence.