It's always been like that, and most products are that way. Some things are more expensive for a reason (e.g. our dairy is much higher quality; growth hormones have never been allowed here), our gas prices go up with our dollar (because petrodollar)... what are we at right now, $1.25/L in Ontario?
Bringing products into a different country isn't as simple as convert to a different currency, and boom, you're done. Canada is a significantly more expensive country to operate in than the US for various reasons, sales are a fraction (population is a tiny fraction too) and a million more reasons.
The US is the world's largest economy, the most integrated economy, most developed supply chain etc. etc. etc. Many things are cheapest in the US vs. anywhere... which is why I buy a ton of stuff there.