Did you not experience the golden age of ICQ, irc, msn chat? It is absolutely possible to form strong friendships entirely online - it just takes the same amount of time and effort to nourish them. I still have fond memories of friendships with the people I used to chat with a couple hours almost daily, and we still know what's going on in each other's lives 20 years later!
Consider the collections of letters from snail mail friendships some classic authors used to maintain. Also purely done in writing.
It sounds to me like you’re just describing the limitations of textual communication, which I agree is limited in all the ways you have written in this post except the last.
But, it’s entirely possible to have thoughtful, deep, honest discussions with individuals over a textual medium and to develop meaningful relationships in that way. I have done so. Often these relationships start in a more open public setting and become more meaningful in a private space, similarly to real life.