It is a little extra work all the time to teach these things than it would be to just do them ourselves.
It's funny, because it seems that way to me now when I think about my 4-year-old, but thinking about my childhood I'm pretty sure my parents didn't feel that way. The "life skills" I learned in my childhood were mostly the result of my parents needing (and demanding

) help. I took apart & fixed the toaster when it broke. I painted (& repainted every summer, getting a bit better at sanding first each time) the back porch. I cooked meals most Sundays (my mom's day off). I was responsible for weeding & watering the garden & harvesting our produce. I helped my mom sew, and later sewed on my own. I did the laundry, cleaned the house, etc., etc.
These days, I let DD help me with almost everything I do, and so she is learning to cook & clean & sew. We'll have a garden next summer, and I'm sure she'll help with that. When she's older, I'm sure she'll help DH work on the car. We don't do much plumbing or carpentry, but perhaps we'll buy a house someday and if we do I'm sure she'll be helping us with that stuff.
I guess what I've seen is that some people just don't do these things on their own. They hire others to do them, and of course kids who are raised like that won't have much opportunity to learn how. But then, I don't necessarily think that these are things that one can't learn later in life if one chooses.