When I changed my political party affiliation in my state, I noticed the option to withhold my address and phone number from the public voter rolls. After choosing this, I don't get door knocks or calls. (I think it was a separate form I filled out and mailed or faxed into the registrar’s office.) This may require you to get a new phone number to be completely effective, and not use that phone number for donations or political activity. This obviously only addresses political calls/texts.
Additionally, I installed an iOS app called SMS Spam Stopper that will filter using on-device heuristics based on a large local library of spammy keywords or phrases, or alternatively you can provide your own keywords or phrases to block. The app has an odd UI, but works. Offending texts are moved into the Junk folder outside of your normal view in Messages that won't trigger notifications or badges. False positives are rare, but occasionally I find missing SMS two-factor codes directed there. Obviously, this is on an iPhone, but I'm sure similar exists on Android.
Further still, I liberally report spam texts and originating phone number to my phone company –– I don't know if all providers do this, but mine has a SMS short code you can forward spam texts to, followed by the offending phone number, and if they get enough reports, they'll block them on their side. This is less effective, because they have an endless supply of phone numbers. I'd like to think an especially analytical spammer may one day group me among phone numbers that never respond and may also be reporting them, getting their numbers shut down prematurely. Apple also provides a link directly in Messages to report and delete spam texts from numbers not in your contacts. So I do that, too.
I do similar to phone calls, and it's all really helped keep my phone from causing frustration. The maintenance decreases dramatically with time.