Ha, I've made good progress on learning the other maintenance.. Sometimes time is the limiting factor and just had to pay to get it done...
I used to do everything myself, and I did/do my best to make time to do it, even when inconvenient.
As I got older, I started doing a few less things because they were a PITA. Muffler or exhaust work? Not any more. Do I have to spend hours laying on my back on the ground? No more. I even started letting others do SOME things as long as it took me less time to earn the money that it was costing me to have someone else do it.
But the most important reason why I try to do everything myself is what I already mentioned: If you do it, you know for a fact it was done right.
I've seen countless instances where the shop didn't do what they were paid to do, literally. I mean, many years ago, I watched a mechanic in the gas station I worked at run out of time to install some struts that a customer brought in to have replaced in his vehicle. The mechanic literally wiped the dirt off the old struts to make them look new, charged the guy for labor and sent him on his way ... and the mechanic KEPT his new struts. I've seen guys charge people for full synthetic oil changes and put dino oil in.
Unless I have a working relationship with a repair shop, I trust nobody when it comes to my vehicles.