That works so long as the government still has more power than a gang of bajillionaires with similar interests. Does it? Seems like we're near a tipping point in that regard, if we haven't already crossed it.
Sure... As long as the army is following the government it's a non-issue. Billionaires are political/industrial/&c. power if you want but they're one "go get them" order away from disappearing forever. It just so happens that for now their goals are somewhat aligned with the gov's.
And even if the gov falls a lot of US three letters agencies are already semi or fully autonomous, and from the few things we know about them they don't fuck around.
Corruption exists, probably on a large scale, but it's not a single coordinated effort, it's more like an army of rats fighting for the crumbs. If even Mexico didn't completely fold against their drug cartels it's not the soy boy Musk & lizard man Zuck dream team who'll destroy the USA
The only way money can protect you is if you literally buy out the entire government, in which case you're basically a monarch.
But yes, that is cold comfort to us plebians.