People make and distribute memes for many reasons. The most obvious and popular of these is basic, stupid entertainment, and many of them succeed in that regard. Some pretend that they are here for the humor, but what they actually want to do is persuade those who them of whatever labored point they are trying to make. There are also some that are essentially trying to sell us things (see: brand Twitter, Barbenheimer).
All of these motivations have varying degrees of validity, but far and away the most important argument for making a meme is that it shares a message that has come from the heart. In other words, you simply had no choice but to do it to 'em. While not every funny internet picture can have such noble intentions, it should be easy to spot those that do. If we're lucky, there might be some examples when we scroll onwards.