Ironically, users themselves are disallowed from rooting their phones. Right to root, is right to repair.
I'm all for having the right to repair. I'm not convinced any of the folks involved ability to root would prevent the situation described.
Unfortunately, the only way to secure my phone because it no longer receives updates is through rooting, but this phone is not a model that can be rooted so my plan is to buy a new phone and root that, and probably remove all text messaging apps or find a way to sandbox them in a secure environment.