You're not prying - that's a reasonable question.
He probably would if I asked him to - but it's him that takes NY Paid Family Leave to take my parents to medical appointments (PFL only pays 67% of your pay and has to be taken in full day increments) and pays for the gas to do so. His boss was letting him do it on the clock but now he has to use PFL.
Between the two of them and all their various appointments with various doctors, he has been running them at least 3 times a month since November, plus when one is in the hospital, he takes the other to visit.
I am more than happy with what he is doing. I hate to drive and especially hate driving with my parents in the car and I really hate missing work for any reason. My brother doesn't mind missing work, likes driving, and puts his ear buds in to tune out my parents - so all good.