It can mean being an affiliate service provider: GC/sub trade, sales broker, debt provider/capital markets, property management, real estate attorney, real estate focused tax professional,  etc. 

That beaing said you should focus on buying a 2-4 unit Multifamily the more doors the more cash flow. 

I'll focus on maintaining the property and optimizing rent increases to ensure consistent returns over the years.

Grad students are calmer, quieter, more focused, usually a bit more money.

I own Granite and Pine Properties - a Direct to Seller Marketing company that focuses on giving sellers 3 selling options. https://graniteandpinere.com/My advertising is word of mouth, social media, SEO, mailers and cold callers.

An example in my experience would be a local/regional foundation with a mission that is aligned directly or indirectly with Affordable Housing AND a longer-term investment horizon with less of a focus on the financial return and more on the "social" return for the community.

Cleveland, Ohio is a great market to focus on for cash flow and specific pockets have gone up 2x and upwards of 4x in the last 5-10 years even!

Consider getting a real estate license and joining a company that focuses on working with investors.

My ultimate focus is not how can I get you rich quickly but rather, wealthy over time.  

That’s why my original post focuses on what can be done within that space to address affordability.