I can't own a home for a fraction of the time.

They work for 1031 exchanges, and provide a way to have fractional ownership of one property, or a portfolio of properties. 

Example:  I've been investing in Medellin, Colombia since 2015 and have realized 20%-40% returns with a fraction of the downside of the US because of the lack of leverage (3% of Colombians have a mortgage.)  

I know to know fractional ownership needs to go through a business if it’s not 50/50 correct?

You can create privacy with ADUs and I would argue only a small fraction of buyers really want a garage.

If I understand it correctly, whole loan investors are limited to investing 10% of their net worth, same as fractional investors, is that your understanding too?

I have heard of notes where there are multiple lenders on the note, as in California where you can do fractionalized notes but I have not heard of them elsewhere.

Cap rates are a fraction of the NOI over the deal price.

They offer a tremendous value for the dollar, in which households can live in nice areas for a fraction of the cost of stick-built homes.

Other competitors are businesses like HouseBuyerNetwork.com and ZBuyer.com.You'll find there are 2 kinds - exclusive leads which only you get and cost maybe $100 each, and non-exclusive leads which are sold to multiple investors at a fraction of the cost, but also a fraction of the value.