If you understood he process by which caller ID names are provided, you would know that they are even less trustworthy than caller ID numbers, which themselves can be easily blocked or spoofed.
The best way to use caller ID names and numbers is to think of them as individual pieces of information that you can use to decide whether you want to answer a call. The absence of a name that is associated with a given number may weight your decision not do answer the call, but you might not always be sufficient, by itself, to serve as the basis for your decision.