Do you mean tertiary education?
America has more famous universities so if he ends up in those, then the US uni is better.
If he is going to a mediocre US university as opposed to a top Canadian university, then Canada is better.
Overall, Canadian universities are generally cheaper but depending on the field, theres more or easier funding in the US.
Both have world class universities. In certain countries, having an American university brand name has some value but as an academic, I am not big on that, however, it could help in employment.
If he is hoping to study and stay in the country, then thats a different discussion and depends on where he comes from, the economy when he graduates, whether there is any change in rules in immigration, etc.
For me a US visa is easier to get than Canadian study visa cause i didn't have to prove that i would come back to the country or maybe i did by telling them my family lives in my home country. In Canada, i think the proof is more extensive.