It’s because it never mattered if she actually won or not, it was all about raking in those campaign donations. The Democratic Party could not care less about winning elections by votes, all they have to do is win by donation totals for them to see it as a victory. Since Harris broke the records on those they’re going to keep her around to see how much money the can wring out of her, and once that starts to dry up they’ll toss her out and start the process over again.