It's crazy how much wages vary, friend of mine is foreman at heavy truck dealership and makes $110k a year working 40 hours a week. I haven't worked for 20/hr since I was 20 years old. I've gotten spoiled because I now say a $400 job isn't even worth getting out of bed for. Cost of living must be really low if wages are that low. Here in construction to get a green laborer you got to start them at $20/hr minimum, and even then it's still really hard to find anyone, if you find a good one you got to get them up to $25/hr to try and keep them. My brother is in concrete and pays a few guys around $40/hr, funny how a few make $100k a year and still live paycheck to paycheck.....
I don't have anywhere close to as many rentals as you, I only have 3 but what i've found is my time is more valuable then doing a lot of things. I've found a good small appliance place that charges me $90 for a service call, not that i've needed but a plumber and electrician who do side work for $40/hr. For many things, you're better off paying a bit more to get a professional they will be faster and it will be better in the long run.
I think one of the reasons you may struggle to find someone good is lack of advancement, you're competing against home builders for example and most people would likely rather work on new homes and in most of those companies they can move up. I think there is plenty of people who are capable of doing minor roof repairs, paint, flooring, etc etc but the pay has to be there, and if no advancement you got to appeal somehow likely better pay. I'd imagine someone maybe near retirement who just wants to put in 40 hours a week and doesn't want to hustle might be a good fit. You also will need to give on some repairs, the chance of finding someone who is good on such a broad range of items is extremely unlikely. Maybe they take forever to change a faucet, but they are a really good taper painter or what not.
Here's the way I look at as a business owner, and I don't want to look down on anyone who chooses to be an employee. But many people are just not ambitious or quick learners, I am dumbfounded on nearly a daily basis how people don't know such basic things. There is a reason many people are employees instead of running their own company. Since I was mid 20's I could do any task involved in building a house, yet there is plenty of grown adults who can barely change a light bulb. Good help is really hard to find and it's getting worse all the time. It's why I gave up trying to hire employees, easier and more profitable to do it myself.