Blocking Spam on iPhone
Two apps that I use are Hiya and Call Control. I have disabled all notifications for each and placed them in folder named spam. Both are using the free version and work good with each other. I also disabled any privacy settings in them that I didn’t like and others were enabled if they helped. Both cannot upload your contacts to their servers because Apple prevents it but they can compare the calling number with your contacts and their databases to see which are potential spam. I have almost zero spam texts and calls. I have set both not to show anything when calls are coming in unless they are already in my contacts. I also have Silence Unknown Callers and iMessage set up the same in iOS settings. All these work together to eliminate spam.