I dunno. For some tasks the time it takes to find somebody else to do it, be available to let the person in/out, and settle payment is much larger than doing it yourself; the lead time is orders of magnitude larger, and doing it yourself gets the bonus that you can do it whenever is best for you, instead of negotiating your agenda with a busy person.
By the time I message 3 electricians, coordinate to let them in the house, get a bid and have someone do the job, and finally get it done, I could've just youtubed and googled my way to doing it myself. Maybe I have to pick up a tool or two along the way but eventually you reach an inflection point where you have the tools you need for multiple jobs. I think the biggest tool purchases I've made in the last 18 months are a brad nailer, a finish nailer, and a 4 ft level.
In my experience, the only way to do less of that in the future is to do more of it now.
This is true...it might be square on one plane and off on the other. That's what the 6 foot long levels are for by the way. It's good to find someone who has the tools and expertise to apprentice from -- either at a local cc or just hire them and ask if you can do some of the work. I went through several contractors before I found the guy I like to work with...I guess its the same in everything...but once you figure stuff out like that blasted little semi-hidden copper pin that's between you and a replacement shower valve, a lot of cost savings can be realized. The first time I replaced that thing, the plumber charged me $270. The second time I replaced it, I paid $19 for a part at home depot and did the rest myself.
I would agree that often projects to fix up your home can be more frustrating than satisfying, unless, like you said, you have the right tools and some prior experience.
Building things that sit in your home (furniture) is likely a bit less frustrating & rewarding, even without the perfect tools and experience.
Start small and work your way up. Make a cutting board, fast forward a couple of years and you'll be building cabinets. Fast forward from that and you'll be shaving backs on a Windsor chair.
However, once I owned a house and had to do renovating/updating, I ultimately found it frustrating.
Some jobs are incredibly frustrating if you don't have the exact tool to make it easier.
The likelihood the angles and geometry of your home are square is, IME, near 0. Even measuring and re-measuring multiple times, I end up with a lot of wasted, mis-cut material.
YMMV, but I always found when you add up the time spent and material cost, it's nearly a wash to just pay someone else to do it.