I think co-ops are the way to go, but I can understand that someone "just" wanting to purchase the good/service might not see the difference between a co-op and corporation like Amazon.

I don't think it's a size issue really, but co-ops generally stay smaller in part due to how they are internally organized compared to a "median" corporation.

I also think that the government actually does a pretty good job at managing things; it's just their failures are public. Private boondoggles might drive many people into bankruptcy, but they aren't publicized any more than absolutely necessary.