Guess Vox never saw this poll on Sinema. Sinema is much more likely to just help the Republican win than necessarily win herself. She's losing head to heads and getting third place in polling too. People across the spectrum don't like her.
She's operating on the same error that a lot of people make in US politics. True independents are less than 10% of the American electorate. Most self-described independents reveal themselves to be consistent Dem/Republican voters, they just like to pretend they are independent. And true independents are pretty politically disengaged to boot. Many don't vote, and many aren't even registered to vote.