iPhones have had speech to text for voicemails for years. Long enough that I can't remember a time without them.
That's quite different from call screening, where it actually picks up the call for you and transcribes what they're saying live and you can choose to pick up the call or ignore it based on their reply.
Sadly only available if your carrier supports it. Here in the Netherlands it doesn’t work with one of the largest carriers (Vodafone) for example. I also don’t know if it’s still English-only.