He could only get wins when all of the other candidates
didn't collude with each other. Those 6 candidates were election stuffing to take focus off of Bernie, to the point that almost all of them pretended to be for single-payer health care. Pretending to support single-payer is literally the only reason that Harris made the national stage. The only reason Buttigieg entered the picture is because he was a nobody that was put up in the same way to split the liberal-left vote for DNC chair from Keith Ellison.
The idea that Bernie's loss is because he "wasn't that popular" withers under the fact that Biden won the election. Biden wasn't even popular among Democratic Party insiders, they just 1) had no leverage to make him stop his campaign, and 2) their preferred candidates like Harris and Buttigieg were far more repulsive to the public than Biden.
The fairness of voting, auctions, etc. wither under collusion.