That's not everyone - some legitimate players may just be short on cash because of projects (I've been there) - but it is a lot of people. 

The only option is to purchase cash and at that point it makes no sense due to the fact that a HYSA account or CD can pay you the same interest rate without having to deal with property management.

Regarding selling these, there is a mortgage note forum here that you can learn to see who the players are in the space. 

The rental had ratty furniture, a record player prominently featured in the marketing but it had no speakers, missing basics items in the kitchen, lots of drunks in the concrete hallways that reverberated right into the bedroom at 2am, a strong odor of urine outside, and more.We have super hosts in this forum that have hundreds of 5-star reviews and are masters of the craft, but I look at their rentals and see they don't have any artwork on the walls, decor is basic, they do nothing to make the guest feel welcome, etc. 

I would like to beat the CD market with it. 

If curious, here are the last two: Jan 2023: Multifamily Real Estate is At Risk of CrashingFeb 2024: Multifamily is at High Risk of Continuing It's Historic CrashI think that the title for my 2025 analysis (likely Jan/Feb publication will be something more like:Multifamily is Finally Going to Hit Rock Bottom in Q2/Q3 2025 - Get Ready to Buy a LOT of itAs usual, I like to publish my draft thoughts here to get input from key players in the space and these forums, especially folks like @Brian Burke, to see if I am missing any high level areas, before I get into the weeds and look at the data more deeply and regionally. 

Someone trying to earn 4-5% return they could get from a bank cd?

(Finance of America, Civic Financial, a few other players) They raised rates on there 30Y product about two weeks ago.

This is why in addition to apathy that bad players get away with as much as they do as frequently as they do.

That depends, but you can see from a bunch of posts on here that so far you're getting shafted performance-wise because a bunch of people aren't getting any dividends during a time when they could easily be earning 4-5% or more in a basic bank CD.