Yeah. The Anschluss-Thing is a little bit more complicated than just "Germany annexed another country because it wanted to".
The German unification was just ~60 years beforehand and during this time it was a real possibility (or at least it was widely discussed) that all german speaking territories would join the newly formed nation, including the german speaking part of Austria-Hungary. The idea was again discussed after the collapse of Austria-Hungary in 1918. So the idea was still in the heads of the people.
Additionally Austria had a strong pro-nazi movement, so a large part of the country just accepted the new leadership.
In present day Canada there is no strong movement to join the US. There is a huge cultural divide. The last time the idea, that Canada should join the US, was seriously discussed over a hundred years ago. The last time the border moved was in 1908. So for basically everyone alive, the US-Canada-Border is just a fact of life.
Cheaper than the free nozzle and hose, that have been rotting in the back of the shed for the past 2 years? I don't think so.