It really depends on this concept of "smart", right? Even if orcas have the same brain capacity in physical/neurological terms, what distinguishes humans is the social aspect. When I say social, I mean thay we have constantly compounding social learning and concretizing that knowledge into technology (going back to sharpened spears tips or pieces of flint). This is the aspect which really sets humans apart, not necessarily the biology itself (though our brains have no doubt evolved over hundreds of thousands of years to depend on this social aspect).

If orcas had such time and ability to pass knowledge on not only through direct communication, but through communicated technology, they might have the same level of intelligence!

To be clear, I'm not making any normative claima about morality or such, I just don't want us to fall into the "biology determines smartness" idea which is undialectical and wrong. With my analysis, and a good normative ethics (which is like "treat beings as the best version of themselves that could exist given time and assistance") we could have a better take.