Unless I am missing something, iPhone doesn't have filtering quite like this. iPhone can filter "Unknown Senders." This is a fairly annoying feature almost as bad as the spam messages themselves.

Google is applying spam filtering. Essentially all the text messages I want come through. All the text messages I don't are a silent notification.

Pixel applies spam filtering on calls too. Few spam calls even make it through the spam filtering. When they do make it through, and you don't recognize the number, you can use Google Assistant to screen the call, which will provide a live transcription of what the caller is saying, all using a local on-device speech recognition system. If you want to pick up, you can do so. Otherwise, you just drop the call.

Teach me. I just switched to iPhone from Google and I get way more spam now (especially texts).

Same. Please, teach us.

Are you sure it's the phone and not the carrier?