Sucky candidates are not merely the product of failing to vote in the primaries. Both parties have systems that favor money and endorsement by legacy establishment figures over popularity, and additional policies are added when a popular antiestablishment candidate slips into office (like Occasio-Cortez).

It's telling in 2020 the DNC elected the most right-wing, establishment candidate that wasn't a far right Billionaire when we had numerous more moderate options.

The US is in the iron grip of boomer conservatives clinging to power as demonstrated by multiple officials succumbing to age and dementia. The people really don't have much say.