Take Turkey, for instance. Mustafa Kemal ruled forcibly in many ways, and almost certainly had dissidents killed. He fought in the Turkish war of Independence so he has blood on his hands one way or another. But I'd seriously question the judgement of any who would claim that his rule was bad for Turkey. He drastically improved the country's institutions and brought is social policies more in line with Western ideals. In the coming years the military would repeatedly overthrow legally legitimate governments to keep the country secular. There's an honest discussion to be had over whether or not Turkey would be in a better person if Erdogan had been overthrown.

Of course in a liberal Western democracy, which I assume you live in, doesn't stand to benefit from regimes like that. But the blanket statement along the lines of "dictators bad, democracies good" is not productive, and sometimes feel like willful ignorance of history. This killing is a poor forecast, but time will tell whether history remembers MBS as Saudi Arabia as an Ataturk or a ineffective, bloody ruler (or, much more likely, as just another average Saudi monarch).