The saying goes if you’re not the customer, you’re the product. Now, you’re both. Every big social media app is testing subscriptions. It's a business model that comes with a perverse incentive. Just like airlines, if you make life worse, more people will pay.
Because it’s far less susceptible to abuse. The block button will deal with anyone being a creep or asshole.
If someone wanted to be abusive, they could come by the address you gave them to send letters or bombard your phone with abuse via the number you gave them for texting.
Even for phones that can block calls and texts coming from a given number, withheld numbers are a thing and they could still sign you up to all sorts of SMS services.
Thanks for the explanation, that makes sense! I didn’t consider all these other possibilities.