The authoritarian promise
We are seeing, in both the east the west, the oligarchs rise to power. Their ability to be captains of industry has made them the heroes of those who have become frustrated with democratic institutions, where bureaucrats inability to get along, has made the governing environment one of toxicity. That is, the oligarch offers the authoritarian promise, of being able to cut through the bullshit of compromise.
The oligarch's expertise in leadership
These are the people who enriched themselves heavily in the private sector and now, as systems face unprecedented lack of confidence, are being relied upon to “save” the systems of government, they are being elected to lead. Of course, the idea that the system needed saving came from media owned by the oligarch's allies.
Putting aside the idea that success in one field will lead to success in a very different one, this is another extension of the concept, that rich will take over, or perhaps take down, democratically principled systems. While its true, the oligarchs, as proven by their success, did become a kind of expert in capitalism, their path was often one of cronyism as opposed to pure experts in system building.
So, they already had connection to government; but, from the business crony angle. And, their path to the top of government had its wheels greased by their existing understanding of where the fault lines lay in a system with corrupt elements.
Strangely, the oligarch's do not hide their intention to enrich themselves
We have seen, some of the oligarchs do not hide that their intention is to enrich themselves. Deals that benefit their privately held companies, are done in plain sight; and, with governments they must also deal with as public servants.
It could be, this is a show of strength. Their ability to flaunt their conflict of interest, is also a sign of their unstoppable power.
Is the rise of the oligarch helpful or hurtful?
Even though there is rule of law that stands against an oligarch, whose main intention is self enrichment, its not clear, if their rise to power, is a temporary thing; a bump in the road for an increasingly rich democracy; or, is the beginning of the end of the system.
Let's not forget, the weakening of the system that lead to the oligarch's ability to use their authoritarian appeal to win elections, was something that has been building for decades. It's still not clear to me, if it just illustrates problems which can then be corrected down the road. (Maybe its easier to correct these problems now that they've been illustrated.)
Certainly, citizens, while they still have power, will have to decide if they are going to jump on the bandwagon of giving up this very power, to strengthen those of the oligarch ; or, whether they will seek to keep a certain amount of weakness in the government. Weakness, that while frustrating, is the check that protects their own freedom.