Quote from @Chris Lo: Which platforms/websites do landlords use to find the rent rate, how long the rental properties have been on the market, and all the details about other rental properties?

Listing on multiple platforms does affect ranking by platforms but not as much as you think.  

What if something changes with how that platform works?

Imagine a platform like Zillow, Redfin, Trulia, etc. where the seller can market their property while receiving assistance in offer recognition/negotiation.

I am looking to dip my toes into rental property investment and find a suitable niche either in the Chicagoland area or Wisconsin (dells up to northwoods).

Additionally, regarding the legal structure, an LLC seems to be the most suitable option for our situation.

These platforms include RentRedi, Stessa, Avail, Innago, Apartments.com (formerly Cozy), and TenantCloud.Pretty much every platform mentioned contains the features you are going to need.

If your medical condition qualifies as a disability and your current living situation isn't suitable, you might have grounds to break your lease without penalty.'

Has anyone bought from the platform?

I continue to see new platforms promise ease of use, lightning-fast approvals, and streamlined processes.