It's entirely possible there was some more nefarious stuff going on, but the consolidation of the Moderate/Center Left "lane" was predicted well in advance of ST. A lot of people laughed at the prospect of "Moderate Voltron" and criticized the punditry for their "Lanes" talk, but in the end it ended up being fairly accurate.
My position is that a lot of the issues Sanders is seeing in 2020 were there in 2016. The one takeaway that I am surprised by is just how much Democrats were willing to vote against Hillary Clinton and elevate Sanders. I figured Biden would do Hillary numbers once the field narrowed, but he's actually doing better than she did—despite her having arguably more support from the establishment. I guess we were blinded by her clout within the party and history of service and really underestimated how flawed she really was—on top of downplaying some of her campaign decisions.
I'm just hear to discuss things in good faith, and try to understand positions I don't necessarily agree with. I was a Bernie supporter in 2016, and I remember how excited I was when he was doing better than anyone expected, and how much it sucked when it became clear he wasn't going to be the nominee. I really do relate to that frustration of feeling you are stuck choosing someone you don't care for or someone who is the antithesis of your beliefs, it's not fun and I wish we as a country could do better.