I often think LOL stands for “I have nothing to say but I feel like you are expecting a response and since LOL requires the smallest amount of time and effort by way of response, that is what I will say.”
Other times, I think it stands for “I know this is a really loaded conversation, especially for texting, so I am going to make a lame attempt at difusing the tension with a halfhearted LOL, despite the fact that you and I both know that nobody is laughing.”
Or sometimes it stands, simply, for “you thought you were funny there, didn’t you?”