Building on Luke’s comment a little (I don’t even know if he’ll see this), I think that’s where other media of social media interaction come into play. For example, something that doesn’t come across in text might come across through a photo tagged or a location checked in.
I feel like we have emoticons and acronyms that help a little with our online communication, but I really agree with your thoughts! Even with my closest friends, I still have a hard time figuring out their emotions through text. As someone who loves to capitalize all letters to show laughter, my friends don’t and I personally would take offense when they respond with “Looool” to my “LOOOL.” Key & Peele, a comedy duo, did a sketch about this exact problem – you should check it out if you have the time!