If I don't recognize a number, I don't answer. Let them leave a message if it's so important. They almost never do. Occasionally, if I am annoyed enough, I will log into my Google Voice, which is under a different number, and call the number back to see whether it's real and if so who it is. Vast majority of the time, it's not even a valid number, or if it is, a recording tells me some flavor of "we are not available to answer your call". So, number spoofing, because of course it would be.
On the other side of the ledger: One of my favorites when I call a bank about an issue is the menu items (which I have to listen to in its entirety because it has recently been changed 😏). The first option is usually, "to check your account balance, press 1", and I'm thinking, how old and/or offline do I have to be to have to call a bank on the phone to see how much money I have with them? Do people actually choose that option often?
Last one: whenever I call a utility like DirecTV for customer service, the first three options are usually about sending them money: "To make a payment by phone, press 1; to make a payment by credit card, press 2; to make a payment by check, press 3 ..."