Q:

What about this political process is useful for making the world great again?

For some reason cynicism, skepticism, and doubt are the communication tactics of the disenfranchised voices in the world.  If government was inclusive, transparent and we voted for ideas instead of people, than ideas out of the wood work would be expressed with the point of view that it creates awareness and empowerment from organizational power if the idea holds merit.  
To create a government that serves the people, we should start by stating our problem in a clear and concise way.  The next step is to allow the world's inhabitants to try to solve it for you.  If solutions get ranked by the amount of likes it receives, then the best solutions would rise to the top of our awareness.
The next step is to make a place for volunteers to sign up or create a transparent organization to ask for volunteers.  So in effect, a person who had a problem could start or join an organization of volunteers that has the goal to coordinate on a solution mentioned.
Good ideas could mature and become forces of nature if the organizational power of volunteerism could create the means to do real good in the world along the lines of improving our situation together.

A:

The current rejection of "mainstream" politics and politicians is a reaction to years of false and broken promises. Every election is full of promises, but as soon as they are over, it's the lobbyists that run the show again. In that environment, you can't trust politicians to implement any idea you vote for. 
But let's assume that the pendulum swings the other way again and governments become more dedicated to implementing measures that help their voters. Voting for individual ideas would be very, very difficult to execute, as you'd likely end up with a top 3 like this:

Lower taxes
Increase Education budgets
Improve medical care

Those are obviously in conflict. (If you still believe lowering taxes boosts the economy enough to pay for anything, google what's happening in Kansas, where they are trying it.) Each idea would need to include how it would be paid for, which not only is beyond most voters to calculate, it would create a web of conflicting interests among these ideas. 
The solution would be to create a coherent set of ideas that together form a blueprint on how to run/improve the country. This brings us back to traditional party platforms, guided by the party's ideology. Those were often worked out in fair detail for voters and would also give an idea of how a government from that party would deal with new issues. 
That system worked quite well for a long time, but it's broken down in recent years in many western countries as the voters interests are being sidelined by the interests of the elite.
If you made elections only about individual ideas, it would probably just unleash a storm of disinformation by all the special interests, until most people stop going to the polls because they are sick of being totally confused. "Coal is clean energy now and solar is dirty? Screw it, I don't care about either".
Come up with a system that allows a coherent budgeted platform of ideas to be voted on and some way to make the people implementing it accountable to the public and you'll get ALL my votes!

