What’s more surprising is I don’t think I have any dust spots either which just can’t be accurate… right??

Have cleaned my R5 once I think as a demo to workshop guests but never had any issues, regular shooting above f/11. But it has a good shutter that drops down on power off and I rarely change lenses in indoor dusty environments

It's that internal, not shutter, curtain, what do you call it? Curtain? Do other mirrorless brands have it?