I'm using Google Messages/SMS app, which can automatically block known spam messages. If a spam happens to get through, you can report and forever block it from within the app. Like spam email, I occasionally check the spam folder for legit messages but so far, everything in there are actual spam messages.

In the last year, I also received a lot of spam messages written in Chinese or some such but those have stopped coming in like since the beginning of this year.

Messages with exclamation marks were automatically blocked by the app, while the ones with an interdictory circle, I have manually blocked.