Caller IDs can be easily spoofed. For example, you may receive a call from what appears to be your bank's fraud department. The person on the other side of the line may warn you of some (fake) suspicious activity and "send you" a one-time security code to verify your identity. In reality, the scammer has already gained access to your email account and is now trying to log onto your bank account, for which they need the one-time code.
There is an existing scam that goes something like that. I probably got some of the details wrong.
I'm like your parent commenter and I would expand on what they call "unknown number".
I don't take calls from "unknown or unexpected caller id". I had someone call me recently that I was actually expecting to call me. But their caller id had their personal name instead of the company I expected it from so I didn't take it. They can leave a message. And they did.
If "my bank" calls me but I don't expect it, the caller id can have my bank's name all it wants. They can leave a message and I'll call them back at a number I find on my card / online.
What might work is if I was expecting my bank to call me and then a scammer calls me with bank caller id. But they'd also need to know what it's about. I've also found that if you're already in contact with large companies and they call you back they very much don't user caller id at all. All their outbound calls say "unknown number". Had this while troubleshooting a phone number transfer.
If I do expect a call from an unknown number and thus take them, I still don't take phone calls with my name. I say things like "Hello". That's it. Then they many times ask "Is this so and so" without explaining who they are, which I find pretty rude and dumb. So my answer to that is: "The question is who you are and what you want". I've had many encounters where the answer from them then makes it clear they are legitimate and they probably thought I was rude but I'd rather be rude than out of my savings. Training for when I'm 80.
by "unknown numbers", I mean "not at my address book", which is pretty small. So this excludes my bank's security department - why would it be there?
And if scammer spoofs my friend's number, I should be able to recognize it's not my friend, or at least understand thar my friend won't need my bank code.
(Sadly modern phones don't make it easy to tell if the label is from your address book or from external syatem. Adding personal prefixes to end of names, like "John (from NY2020 party)" helps a lot with this.)
There is an existing scam that goes something like that. I probably got some of the details wrong.
Bottom line: do not trust any incoming calls.