The main problem I see is the 'collective' part, or rather how to achieve it.
Many people want similar things but feel powerless and rightfully so.
If we could create some sort of protocol or platform that enables positive communication it might go a long way.

There was the idea posted at r/abetterworld which I think is a great basis for this, if it could be created.

This type of system would allow many people to coalesce their views and wants, then plan steps needs to achieve those goals.
Without something like this, that brings people together through common views I don't know how to get what OP wants. Divisive sites bring people together in one place but don't units ideas, the consensus engine could change the world. If it existed in a free and open way.