What better alternatives are you thinking of? An intelligent, compassionate, eco-friendly and forward-thinking dictator would be great I guess, but historically that's not the ones emerging on top.
the only one that has so far been "good" has been the singaporean authoritarian regime (yes, they are "authoritarean").
But even if they're good and benevolent so far, there's zero guarantee that the next leader, or the next generation of them, will remain true.
That's why even though majoritarian gov't are bad, they're the least worst. Not to mention that if the elected gov't is bad, it's becaue the people doing the electing didn't put in enough civic responsibility as a collective.
Politicians would have more shit to throw around, yes, but hopefully the worst of them will look elsewhere for the easy money if it can't be had that easily in public office.
We are mostly ignorant, and we vote, consume, act and live that way. We choose to be that way, and so good things won't last long in our collective hands.