Even if you don't already live in a high-corruption society, you can either spend some of your wealth introducing that corruption (which pays dividends), or you can just go somewhere else that's already high-corruption and bribe your way into immediate permanent residence.
Live in a democracy? Just buy public opinion by leveraging your wealth into a highly-profitable propaganda network, which will also give you an appealing platform for opportunist would-be government officials, who will then owe you, making your bribes cheaper. Maybe you can even just directly blackmail or entrap them along the way, so you don't even have to pay.
Live in an autocracy? Buy enough weaponry and PMCs to insulate yourself or even rival the government itself, or just buy the autocrat's favor directly.
Live in an oligarchy? Psh, your work is already done. Just use the system as it's designed: to be exploited by your vast wealth.