I think that if we all thought the same thing about where we come from, we wouldn't be human. Would the world be better without religion? No.

if, for example, we all looked exactly the same, the world should not have any more prejudice or discrimination because of appearance, right? It would be a better place, just because we would have less differences among us, right? But looking exactly the same doesn't mean we would be better people. In fact, I'm sure we would still discriminate about he way we dress, talk, walk, etc.

So, in the end, looking the same wouldn't make that much of a difference.

The same thing happens with atheism. If we all thought the same about one thing, we would find other differences and other things to divide us because in the end we are the same people. Atheism wouldn't neither fix that nor make it better.

So no, we shouldn't all be atheists because it wouldn't change a thing about anything.

More than a side-effect, corruption is part of any political system. That's why the different parts of the government control each other, to balance each other out and avoid the corrupt ones from taking over the countries in a not so honest way. And power doesn't necessarily come with corruption, but you it's common to become corrupt to get power.