Yes, the DNC would rather lose outright than pivot to the left, because their donors would rather have republicans win than leftists. The DNC and GOP collaborate against third parties as well. In order to move beyond this problem, we need to organize outside the bounds of Electoralism, and do so on a constant basis, not just in the lead-up to election day. Reading theory helps this greatly, I keep an introduction to Marxism list on hand if anyone wants to read it that I can link.
Why would you ever vote for fake rightoids playing the numbers game instead of the genuine article? On the other hand a strong left alternative with big ideas might actually convince people.
What convinces people is organizing. Practice reinforces social knowledge. Reading theory is critical as well, but organizing and putting theory to practice is what spreads.
Lot of conservatives out there who aren't MAGA. In an election against any other "normal" Republican you'd be 100% correct, but against Trump I can see the logic of targeting frustrated moderates over progressives, considering how unreliable progressives are on election day.