I can find references to the built in spam filter for Google Messages going back to at least the beginning of 2019, so this isn't exactly a new feature. I haven't noticed it myself, but as someone who has received a spam message maybe once or twice in his life, I don't think SMS spam filtering is something I would've come up with were I to work on an SMS messenger. Maybe as an extended blocking feature?

I personally use Signal for my SMS messages, maybe that's filtering messages for me. Pretty neat to be able to use an alternative messenger as the system messenger app to be honest, since I'm going to install Signal on my phone anyway!

Google's Android messaging app does just that and has for many years. I had no idea that iOS didn't.

it's patently absurd when people use patently as a filler word.