iOS 13 has been released, but I recommend waiting a bit before installing it till some bugs get worked out. In the meantime, read this article on some things you may want to try out when you do install it.
When you do update to iOS 13, here is a new feature -- silence unknown callers -- that will reduce robo calls. This feature isn't enabled by default, so turn it on in your iPhone. One thing to do before activating this feature is to put doctors, dentists, etc., in your contacts list so their calls will come through. The article explains some other features you can enable as well.