My opinion on the cause of stuttering

My opinion on the cause of stuttering The cause of stuttering is supposedly unknown but I think at this point it's very obvious. In particular I'm talking about speech blocks which are the worst of stuttering in my opinion as every single person to of ever spoken has stuttered or stumbled when talking and that dosent make them a stutterer. Speech blocks on the other hand you can't play off as just your way of speaking, it's obvious to the person listening and it's mental torture for the person speaking. It's not uncommon for "ordinary people" to not be able to talk from time to time for example if they are on stage. When thinking about this I always think of the Eminem lyrics "he opens his mouth but the words won't come out". I know it's a movie but it happens in real life too and it happens to people who aren't stutterers. In these moments of extreme anxiety the body seizes up. This makes me think that stutterers just have a very extreme form of stage fright. This isn't a ground breaking idea and I can't think of any arguments against it. I'd love to hear your opinion on it🙏