Yeah except new cars you don't have access to the battery (they are starting to make the engine 'protected') and even changing a tire is more rare as many manufacturers are shipping a repair kit vs a spare wheel. Most also have roadside assistance (or your insurance has) which makes it easier.
Most people want a car to go from A to B, many times, if every few years (I only had a blown tire in 20 years driving) they have to call someone to help them, it makes much more sense than spend the time to learn how to do it themselves. Same with computers, they don't want to know how the bytes get into ram, they want to play Doom or write a school paper. There is no need for them to learn all that.