The problem with people like Zohran Mamdani, Graham Platner, and Omar Fateh is that they’re unknown and untested. Few will ever vote for someone with no experience. Well, no one that isn’t a republican or thinks like one anyway.
You’re projecting. You would not vote for someone with no experience because you have a conservative-style risk aversion. When the choice is between a known and unknown quantity - and the known quantity is proven to be corrupt and/or impotent - the unknown quantity is preferable. Zohran Mamdani’s primary victory is exemplary of this.
50 years of trained helplessness. You’ve seen every attempt at bucking the Democratic establishment fail and at some point must have come to the conclusion that trying can only ever cause harm. It’s an understandable cynicism given the circumstances you’ve been living through, but you’ve forgotten that circumstances change.