I do both STOP and also report it as Junk in IOS. It has had some success. At least I've been getting lot less election related texts. Use to be that I got 6-8 messages a day from either Presidential candidate or both or down ballot local elections. Now its down to maybe couple of texts a week. Even those look like they're related to PACs and not directly from the campaigns of the candidates. However, I still get the scammer related spam.