Abolish trade barriers between the provinces: a false good idea

Since the announcement of American prices against Canada, many have proposed that trade barriers between the provinces have been abolished.
However, the idea of replacing an American market with more than 330 million consumers with a Canadian market of just 40 million is doubtful. Especially since these barriers are not tariffs, in the sense that products from the rest of Canada are not taxed when they entered Quebec and vice versa. These barriers are rather regulatory. To abolish them, Quebec should renounce freely exercising its most important competence, that on ownership and civil rights, which allows it to have rules in matters of language and civil law, to mention only two Examples.
Concretely, it would be a question, among other things, of allowing the members of the professional orders of the other provinces to practice in Quebec by ignoring the requirement of knowledge of the French provided for by law 101 and therefore of fundamental law to professional services in French.
According to the promoters of this idea, the abolition of these barriers would cost nothing and report a lot. On the contrary, European experience shows that the harmonization processes cost expensive, in addition to being undemocratic and ineffective. Because rather than having rules developed by elected officials in broad daylight, a process of harmonization supposes rules developed by countless technocrats overpayed during obscure interstate encounters, where lobbies are more influential than simple citizens.
As for the so -called economic benefits, low European growth after decades of harmonization shows that they are limited. The abolition of these barriers can even be economically harmful, because for each barrier that blocks a business from the rest of the country, there is a Quebec company that takes advantage of it and whose business model takes into account this barrier. The abolition of these barriers should therefore be accompanied by a vast program to help Quebec companies … which would be extremely expensive.