For what it’s worth I usually try to call back these anonymous callers from a secure burner phone but when you call this number it says “check the number and dial again….” in a female AI style voice.

Why don’t any of these numbers that continue to call me ever appear in a search of reverse number lookup if they are legitimate businesses?

That’s because they are not legitimate businesses.

This number called be. Let it go to Vmail. Didn't leave a message
Likely a scammer using a VoIP number

This number just called me. I let it ring out and reported it.