The internet can provide some amount of valuable community and support, but it's limited. Words in text can only convey so much. You can't be held. You can't shout and scream and be irrational. It's easier to hide than confront difficult emotions.
Therapy is so valuable, and its stigmatization hurts us all, but it's also limited. It's just one person, with one set of beliefs. They aren't there with you in the heat of a difficult situation. And honestly, there's something so gross about having to pay hundreds of dollars just to find someone to be real with.