Semi-recently I renewed my voter registration. When I checked the details in my profile I noticed that there wasn’t a little red asterisk next to the phone number field - it wasn’t required! Curious, I clicked the little “i in a blue circle indicating more information” thing (do those have an actual name?), and it said that field was public information, and would be shared with some political groups, etc. I immediately deleted my phone number, and I’ve noticed the political texts have slowed down noticeably.

I’m not saying that’s your problem, but it’s worth checking.