I do most everything myself, mostly because I am cheap and I also feel good about my accomplishments, but also because I can stretch the budget a lot farther.
The big difference between me and a pro, other than cost to me of course, isn't the results, it is time, as I will in most cases take longer to do the job, and also not consider it done until everything is right.
Have done a lot of plumbing, we just did a full bathroom remodel, and not just replace fixtures, moved everything around, and a new garage addition on our 65 year old mid century ranch house, also took a closet out, drywall, trim, electric, heated tile floor in the bathroom. Built a fence, learned about underground sprinklers which I didn't have at the old place. etc., etc.
I Hire out concrete work, and bigger drywall jobs (I can do them, but takes me 3x as long as a pro), as well as bricklaying (that one I have never tried, but didn't want my learning efforts on permanent display, also I am sure I would be too slow.)
The "kids" (probably late 30s) that bought our old house said they would paint some rooms. They were not rich by any means, buying their first house, but she was going to hire it out, they "just don't do stuff like that". Painting was one of the first DIY jobs and I did, my wife does it to, nobody taught us, just did it. Still one of the easiest DIY jobs out there, our "old" house was newer, no wall repairs needed, just paint.
lost a window when we put the garage in, had to match the old paneling (old to the right of the corner, new to the left)
new fence
trimming out the garage addition
new bathroom
4' crawl space, not easy on the back.
There is much more, makes me tired thinking about it, glad to be back to cars for the most part now.
One thing I will add, there were a few more things I tried to contract out, but contractors around here are something else, hard to get estimates, or commit to a time to work, got tired of dealing with them and would do it myself.
Kids these days.