Thanks for this perspective. I am one of these mismatched PhD students. When I entered 6 years ago, no professors in my department had time to advise me. The professor for whom I was a GTA took pity on me after two years of rejection, and now serves as my committee chair despite having little to no expertise in my field. I am coadvised through a different department, but again, my coadvisor has little overlap with my interests. I am nearing completion, but stumbling over the lack of support, technical leadership, and community of practice. I am unconvinced that my proposed dissertation is meritorious or valuable in any way, but the only advise my advisors can give is “persist and finish quickly” because I am more expert than both of them. Defending feels like a gamble. The bitterness that comes from poor-fit advising is real, even when both advisors are earnestly doing their best. I wish I had learned this lesson sooner and quit with a master’s when I had the chance.