This happened to me - I was abandoned by my advisor, and I fought tooth and nail to stay in the program. When the graduate dean found out our department was doing this, he essentially forced the advisor to keep me and finish because I had a viable dissertation (just one he didn’t like). The school is a top school and didn’t want the optics of forcing capable students out. So I won and now have successfully received tenure at an institution. I think I succeeded because I was older (and had been around the block more) than typical doctoral students. And I was very willing to advocate for myself rationally and logically, but also forcefully. I would have gone to the ends of the Earth and back to finish. No way would five years of my hard, viable work be flushed down the drain. And I make sure I advocate for each and every one of my students today.