I don’t answer the phone unless I know who it is. Robo calls seem to go in cycles. I can go a week or so without them, then get a few a day for a while. It hasn’t been bad enough to limit incoming calls to favorites or all contacts. I just tap the power button to mute the call. If it is important they will leave a message.
The only time I answer a call from an unknown caller is if I am reasonably certain it is a scam then I answer and immediately hang up so I don’t have to waste time cleaning out voicemail.