We do fractional interest loans in California. 

By structuring your deal so that they make their profits after and subject to you making your profits, your likelihood of your success increase many fold.Of course taking the second "path" doesn't give you the same profit potential as developing your own skills and going it alone - but it doesn't require a fraction of the effort either.Good luck with your ventures.

Lately, I have been working on my retirement plan - where to live, multiple locations, one location, fractional ownership, rent vs buy ?? 

All the cash flow markets selling will be at fraction of purchase price.

When you compare it with stocks:100K invested in an index fund that earns 10% a year over 30 years, gives me: 1,744,940.22To make it even worse, a 4% safe withdrawal rate for the actual value of what my assets would be in these two scenarios, I'm making about 900K a year in SWR eligible funds, compared to a paltry fraction of that with my real estate, which is ultimately a job.

But that is only a fraction of what those monthly payments would have been.

Private street level investors are but a mere fraction of that market.  

Understand - American government, in the fractional reserve fiat system you talked about, runs on debt.

The save and use compound interest model could take a life time and you may only reach a fraction of the 100M net worth figure or you need luck like others have mentioned.The quickest way is to do what the rich do and that is to do what JJ Marco focuses on in his book the Millionaire fastlane by either focusing on the 1) Magnitude or the 2) speed/velocity.Increasing Magnitude would be like increasing the ticket item size so if you're a real estate agent instead of selling 250k homes you sell luxury items that you receive your 2.5% commission off of 10,000,000 instead.Increasing Speed/velocity would be how many times you can transact and earn that commission above, profit above in whatever business model it is  whether you're a RE agent, you're selling burgers, or widgets. 

But then again maybe the MLS is the one place I need to stop looking.Sometimes in rural and low valued prop areas, MLS comps are only a fraction of the the recent sales.