What do you mean by "made the world a worse place"? Worse than it was before democracy and liberalism started spreading, i.e. pre-1700s? Or worse today than it would have been today if democracy and liberalism hadn't spread? The first question seems easy (we're more peaceful and prosperous than the past), the second a nearly impossible counterfactual, depending heavily on what government systems and philosophies we'd have instead.

A quick talking point is that colonial Rhodesia used to be practically a first-world country. (Is now zimbabwe). Same story for most of the third world, AFAIK. The fact that only rich imperialist powers happen to be progressive democracies isn't much evidence; if democracy fails in 9 cases out of 10, and fails in a way that degenerates to third-world barbarism, you will see a few successful progressive democracies, and a lot of third-world hellholes. Mind you, this is not an argument for tearing down democracy, merely that it could be the case that setting up a new democracy is a bad idea (see afganistan, iraq, etc). Further, if you accept the cynical take, realizing that you live in a brainwashing theocracy ought to affect your intuitions about what looks like "doing a pretty good job". Have you taken this into account? These are not my opinions. Being neither a historian, political philosopher, or government employee, I am not qualified to have opinions on this subject.