For me it is mostly a time issue, I never seem to have enough time to do most of my own work unfortunately. I used to do brake stuff myself, and even alignment with strings and corner balancing, but I sold all that stuff now, and my car gets serviced by trusted mechanics now, even oil changes and brakes
You don't have an opyion in your poll for ppl like me, which is hard to imagine, I know; I don't even wash and wax, dealer does that perfectly for me.