If you can, turn off unknown callers from being able to reach you.

I’ve done this and it’s been wonderful. The spams have actually decreased significantly since I don’t answer the phone for them at all anymore.

It’s under Settings > Phone (have to go into Apps in iOS 18) > Silence Unknown Callers

Anyone who is not in your contacts gets a ring but the ring doesn’t go to you so you don’t hear it and don’t answer. They can leave a voicemail but scammers never leave me voicemails.