With choices of two major political parties, US voters have do not have granularity to approve or disapprove long term/chronic/fringe issues or issues that disproportionately affect a small minority of the population.
I'm not sure it's a deeper structural issue. The issue is actually pretty simple; first-past-the-post voting. This automatically leads to a two-party system.
Canada currently has 338 MPs and over 80% (!) of those (278) belong to one of two majority parties.
So yes, in theory Canada has a multi party system. In practice this multi party system is severely damaged by the effects of the FPTP voting system.
There are mathematical reasons for FPTP to result in two party systems. [0] explains it pretty well. There don't have to be deeper underlying stuctural reasons for the dichotomy.
So to combat two party systems, replacing FPTP with an alternative voting system seems a pretty reasonable step.
This is a problem. That being said, several major states have a good amount of direct democracy, including allowing for state constitutional changes, and there are often more than two viable candidates regardless of the letter after their name. I think this is a plausible way out of the two-party two-ideology stronghold that incites further polarization. Where I vote, between these two factors I don't usually think about a party because there may be 4-6 different candidates with relatively different platforms listed under two parties, and 10-20 referenda listed under that with no party.
There is difference between voters choosing forced prison labor and voters given the choice between two parties and being intentionally misled and misinformed about what the parties are actually doing.