In the US, members of Congress spend a truly unfathomable amount of time fundraising---as much as six hours a day. There's also just the fact that the issues before Congress are numerous and complicated, and staffing hasn't kept up. In fact research staff were cut significantly back in the 90s.

And the real trouble is that once everyone's gotten (understandably!) cynical about the institution, most of the stuff that would help (more staffing, public financing of campaigns) feels like giving more money to crooks. So we go on this way despite everybody knowing the problem and the solutions being not that complicated, or even very expensive in the grand scheme.