I'm not OP but I use Snapchat a lot to chat. I like that the messages are not saved, it feels more natural for me as in I don't have to "think" too much about what I write, just as talking. This way it feels less staged, you can compare it to photos on insta vs photos on snap (likes and permanent vs none of that). With text it's obviously to a lesser extend but still. No one can go through years of messages and see what i said back then.