Comment by toast0

At least in my area, the problem is labor costs. If you can do things yourself, it's great. If you need a mechanic to do it, you're looking at a big expense, because mechanic labor is expensive and there's a lot more covers and harder to get to parts these days. 'Maintenance free' transmissions are very common in newer cars, and they do tend to need less maintenance, but when they do, there's often not a great way to access them. Etc.