That's the oversimplification that wraps things up nicely and doesn't require digging any deeper. Like when people think Kim Jong Un is necessarily just a madman without realizing that playing the madman is the perfect defense against outside interference. Give up their nukes? Ukraine did that, they even have a signed treaty with Russia for this. Iran signed a piece of paper with the US too. That turned out well for everyone who is a superpower.
Authoritarianism isn't required to get richer than you could otherwise as an already powerful person. Look at democratic countries (all still having a measure of corruption) where having slightly more money and power than most people gives you access to huge wealth and immunity from the law, a positive feedback loop where money begets money.
Did the Sacklers need to be crazy dictators to get even richer while throwing a wad of cash at the government in exchange for full immunity? Regular people get civil asset forfeiture but for rich people there no law to find them guilty and take back all the money, the only way is to negotiate a consolation settlement? Obviously lobbying for donations or plain old influence peddling will get you incredibly far, maybe even further than dictatorship.
Putin doesn't need this level of authority to stay rich and powerful as a former member of the intelligence community. He needs it because he has grandiose dreams of Russian imperialism, bringing them back to former superpower glory after seeing that the post USSR breakup times and trying to integrate into the Western world made them play fifth fiddle. This needs the authoritarianism because Russia is lacking the other quality of life elements to afford selling the "glory" aspect to people.
It's like deciding to be the CEO of your own company rather than the middle manager in somene else's even if the pay is the same. Only your employees are stuck suffering there.