We need radical changes, but the politicians are too afraid or are too corrupt for that.

Sounds like your population needs a better sense of civic duty honestly. See how you put yourself apart from 'politicians'? Politicians are people. They come from people. They sought out that political office. So could you if you put your mind to it.

Figure out what that radical change should be. Figure out where the problems are. That's everyone's duty in a democracy. Nobody is entitled to 'better politicians'. You are only entitled to a democratic system that allows you to become an agent of change (politician). If your ideas are good enough, you should be able to convince others of that.

Even if you think becoming a politician is too lofty of a goal, your conversations with your fellow countrymen shouldn't stop at 'yup, it's all fucked up and sucks'. It's everyone's duty to be thinking of possible solutions and roadmaps to effect the change necessary to improve conditions for everyone.