Signed in to say this. I built a shed in my backyard as one of my first DIY projects and also used screws. Not even structural screws, just standard 3” construction screws. The thing is solid. No one is walking around on it. It isn’t under the same stresses as a two story house. Like you said, it’s a box!

I did my research, understood that nails provide better strength. I chose screws. So do many other shed builders.