I mean, it seems pretty obvious to me at this point that Warren has a massive fucking grudge against Sanders - literally all of the fighting between the two of them as candidates has been explicitly one-way. Warren was leading in the fall and then Bernie surged as she collapsed for a variety of reasons. If Bernie wasn't in the race, she would likely be going head-to-head with Biden and be the leading progressive candidate considering a huge portion of Bernie's supporters have her as their second choice, but since his support base is much more solid than hers, that is literally never going to happen at this point.
She isn't going to be the nominee, she isn't going to magically surge out of nowhere unless Bernie literally dies, and her continued desperation is just pathetic to watch. If the roles were reversed and Bernie was hanging on to his 9-12%, siphoning votes predominantly away from Warren as she was the one struggling to hold a lead in the overall primary race, there would be a flood of people, particularly here, calling on him to quit because he was only splitting the left-wing vote and they would be completely right to do so. This entire thing is ridiculous. All of the arguments I've heard here against Sanders now apply to Warren with near 100% applicability. She is the one being divisive, she is the one splitting the vote, she is the one desperately continuing on despite no path to the nomination, she is the one compromising her supposed ideals for power, etc. If she doesn't drop out after ST, assuming she doesn't randomly do incredibly well out of nowhere, her presence in the race serves only bad purposes.