For those educated on this, how do you tell what's actually useful automation long term vs. what’s just trendy that might fizzle out? 

Quote from @Aaron Maxwell: Is there a way I can use ai or any apps to help me automate my marketing campaigns, sending emails, texts , reminding me when to contact owners etc?

September of 2015 I paid $3,495 to Tracy @ Property Mob for the "The Key" Real Estate Automation Implementation Program, I ended up cancelling everything they set up, in my opinion it was not worth the cost.......I know at least 3 others that paid for the same and were super dissatisfied....

Investment Info:

Single-family residence other investment.

Purchase price: $260,000

Cash invested: $100,000

4 bed/2.5bath home used as STR purchased in 2022. Listed on Airbnb, VRBO and booking.com. ...

Most payments are automated, but Quickbooks only has so much automation. 

I suggest checking out lob.com for automated mailing of notices.

Homeowner.ai seems to have a pretty accurate automated valuation tool.  

That said, many landlords, especially those starting out, struggle with scattered communication, tracking/automating rent collection, and organization.

Also, which features do you find essential for the five-unit mark and beyond such as cash flow tracking, automated expense categorization, KPI’s, etc.?

As an STR/MTR host & co-host in Metro Atlanta, I think self-managing in a tourist area can work well, especially if you automate as much as possible (smart locks, dynamic pricing, messaging templates, etc.).Since you're just getting started, focusing on a turnkey or lightly updated property might make the transition easier.