It’s not due to incompetence. The US has never been a democracy by design. In fact, it’s working as intended. Previously:

The US government was never not captured by the bourgeoisie, because the US was born of a bourgeois revolution[1]. The wealthy, white, male, land-owning, largely slave-owning Founding Fathers constructed a bourgeois state with “checks and balances” against the “tyranny of the majority”. It was never meant to represent the majority—the working class—and it never has, despite eventually allowing women and non-whites (at least those not disenfranchised by the carceral system) to vote. BBC: [Princeton & Northwestern] Study: US is an oligarchy, not a democracy