This problem is solved by software like gradescope. Makes grading extremely fast and much more consistent (because of easy rubric adjustments on the fly). This is more concerning a STEM exam, admittedly I don't know how well this works on humanities essays.
Gradescope partially solves the problem. There are certain kinds of questions that are more amenable to rigid rubrics (e.g., techniques of integration in a beginning calculus course) where the space of correct solutions is rather limited. Once the material gets more advanced, the space of correct (and partially correct) solutions gets really large, fast. One could design exam questions to restrict the solution space, but sometimes at the cost of testing real understanding. Also, at that point giving partial credit with Gradescope-style rubrics is not always straightforward (not impossible, but not trivial).