What little does get sold is typically traded off-market. 

There are many ways to trade the use of sprinklers in a building. 

Take into example of financial advisor vs. trading independently.

Regardless if it is MF or SFR, I always look for value add opportunities, without that, I am likely not interested.I will also point out that each investor has his/her own goals, desires, skill sets and as such, there is no right or wrong answer here.SFR Pros - Financing is often easier.

What skills to you have? 

The keys that I’ve discovered up north is to build your relationships with realtors and people in the trades to get the best beat on what’s for sale off market, and to keep an open mind out for alternative uses for buildings maybe no one else wants that you can purchase for a discount and then repurpose easily to fit your needs.

Chicago multifamily is mostly trading in the 5-6.5 cap range with the occasional "7 cap" when there is a TON of deferred maintenance.

Welcome to BP and specifically Iowa Real Estat :) Sounds like you have a fantastic skill set that is needed by most people in the real estate investing world (construction and grit).

But like you said, you’d be trading your time, headspace and still not positive of the 50% return which could go to negative as well.  

One other caution, when you say "I'm 22 and I have done excellent in my stock and crypto investing", don't confuse luck for skill.