Fellow Canadians - where is Trump right about us abusing our trade relationships?

I am Canadian and I think that with every attack on us, there must be also a moment of reckoning and introspection.

Trump has been wrecking havoc on our relationship and economy, however, there are some truths to what he states.

For example, Canada is very protectionist of our "merchants" (i.e. a powerful group of lobbyists) who have helped set up a duties and tariffs for anything imported into Canada past a ridiculously-low "de minimis", which the U.S. does not impose on us. Why in Canada has not naively ordered something from a US retailer to have it held at ramson by the courrier, who then charges us all sorts of protectionist taxes (the stingiest in the developed world). A US consumer buying from Canada is not subject to this. Ours is $20, compared to the $800 in the USA. Also, as the article states, we "spend dollars to collect dimes": as of the 2016 date of the cited article, Canada spends $166 million to make the system collect $39 million. Trump is right here about Canada having its cake and eating it.

I believe there is a similar example with dairy. Our governments bend over backwards for the dairy cartels/oligopolies in the interest of "protecting the industry". I believe this was renegotiated after NAFTA was dissolved, but still, another long-standing abuse from Canada. We can't get mad at the USA for being "protectionistic" and slapping tariffs on us when we've been doing it for ages.

What other sustained examples do you have where Trump is factually right about how Canada wants to have it only our way, while taking advantage of the fact that the USA has not been reciprocal with such measures?