I used to do all the work on my vehicles. I like mechanical things.
But these days time is more limited. I work more hours, and want to spend my free time with my kids doing fun stuff. I still love building projects, and so do my kids, so rather than spend time changing my own oil and and various other auto-related tasks, I just let the auto mechanics do it.
The two exceptions are, I always do my own brakes because it's easy and I can save several hundred dollars, and I also can de-cloud my headlight lenses in about 20 seconds using aluminum polish, and my Makita buffer/compounder. My next door neighbor paid a shop $100 to do that, and cursed like a sailor when I showed him how to do it in 20 seconds.
Other than that, though, I'd rather spend my "home-engineering" time building things with my kids.