Smarter feels like a bad word to use - I specifically dialed into problem solving because I think that's one place we can accurately differentiate but "smarts" is an incredibly broad concept. We're better at certain things because of specialization and long education but worse at other things because we're obviously not training our motor skills to do different things from birth - it's like folks who can skin mangos in a single cut, it can be learned but most of us aren't going to learn it.

Ancient Egypt did have public schools and a semi-meritocratic scribe class so formal education was a thing which makes it easier to compare in contrast to areas that revolved entirely around apprenticeship like the more nomadic contemporaries would be.

Also, we do have a much more balanced diet growing up but if we did travel back to ancient Egypt there might be dietary issues trying to maintain our extra mass - the lack of access to diverse fruits and vegetables might wreck havoc on our bodies... you can look to extreme contemporary diets for any evidence of that you'd like to see.