What it's supposed to be for is in direct contrast to what it was used for, which is to suspect rights. And that's exactly what was determined later on by the courts that they did infringe on the rights of Canadians.
0: https://laws-lois.justice.gc.ca/eng/acts/e-4.5/page-1.html
1: https://www.justice.gc.ca/eng/trans/bm-mb/other-autre/emerge...
As for legal responsibility and repercussions, that's a process that is still in motion. The law moves slowly in Canada.
1. in Cambie Surgeries Corporation v British Columbia (https://en.wikipedia.org/wiki/Cambie_Surgeries_Corporation_v...), where a private clinic challenged the province's ban on any private care whatsoever for procedures that are provided by the public system on the grounds that if the province bans procedures but then also rations access to those procedures to the point that they're inaccessible for many patients, it constitutes a violation of our charter right to life and equal protection.
It seems they were able to successfully argue that this does constitute a violation of our rights, but the decision says it's okay because it's done with the intent to preserve the equitable access to healthcare for the general public.
2. Employees in union shops are forced to join the union. This is arguably a violation of our right to freedom of association, but the supreme court says that it's okay if it does because "the objective of this violation is to promote industrial peace through the encouragement of free collective bargaining". https://en.wikipedia.org/wiki/Rand_formula#Freedom_of_associ...
3. https://en.wikipedia.org/wiki/R_v_Comeau, a famous case where a guy bought beer in Quebec and drove it to New Brunswick (for personal consumption) and was fined. His case argued that that's a violation of section 121 of the Canadian Constitution 1867 which states as black and white as can be:
121 All Articles of the Growth, Produce, or Manufacture of any one of the Provinces shall, from and after the Union, be admitted free into each of the other Provinces.
But the Supreme court ruled that it's not enough for provinces to ban goods from entering their province for it to count as a violation, it must be a ban which has no other purpose but to impede interprovincial trade. But that means that this section is completely useless because a justification for protectionism can always be found or made up on an ad-hoc basis.
Basically, Canadians have no rights whatsoever. Our entire legal system doesn't sit on anything fundamental it's all just vibes and arbitrary whims of the justices of the day. Our charter and constitution are so full of explicit holes like the notwithstanding clause, that they're rendered almost meaningless even on their own terms, and then any other violations will be excused on the flimsiest grounds.
Your hypothetical isn't even always the case. When unions form, usually there are employees there that don't want to subject themselves to the union, but are forced to, so they didn't "join a workplace with a union" at all.
(2) Again, we balance the well-being of society against individual rights. In this case, defending collective bargaining is a reasonable action when considering that there is _plenty_ of other opportunities for work. Don't like unions, don't join one and find work elsewhere.
(3) Per the court ruling, Canada does not have a guarantee of internal _unlimited_ free trade; it only prohibits tariffs on internal trade. Whether or not that is a good thing is hotly debated, and a matter of current policy.
> Our entire legal system doesn't sit on anything fundamental it's all just vibes and arbitrary whims of the justices of the day.
It's Common Law, not Civil; and so it's based on layers of legislation and court proceedings.
In practice, we have plenty of strong protections for our rights, but those protections break down when our behaviour becomes harmful to broader society. Whether or not you think that's a good thing probably indicates where you are on the line between classical liberalism and toryism.