… You seem to be forgetting about the difference between the width of the projectile and the actual force that it imparts.

A 5.56 round is comparable width, but it’s also moving significantly faster due to the “it’s a rifle round do I really need to explain this?” factor. It was designed and selected with criteria like “can enter a steel military helmet at 500 yards”.
Less recoil at high rates of fire with equivalent lethality are other criteria.

A rifle having ease of use doesn’t somehow make it safer than one that’s harder to maintain. I’m honestly not even sure what you’re thinking with that point. In your mind is a flintlock more dangerous because it’s tricky to use?

Yes, it’s a small bore military rifle designed with military lethality criteria with the requirement of easy operation and high accuracy at increased rates of fire.

What do you get out of trying to pretend there’s no real difference between a pistol and a rifle?