Supply management does have its problems, but given the involvement of imperfect humans nothing will be without problems. Canadian pork, beef, and vegetable farmers that I personally know also complain that they can't enact supply management for their sector. They also envy the appearance of high profits, an easy life, and government subsidies & bailouts (yes, Canadian dairy farmers still receive those) for those in a supply managed sector.
At the end of the day, consumers get stable and somewhat realistic prices and supply, while farmers also get stable income.
> consumers get stable and somewhat realistic prices [...] while farmers also get stable income.
Which? You can't have both. Input costs are subject to the whims of non-supply managed markets. When, say, input costs rise either the farmer has to absorb that cost (unstable income), or the cost has to be passed on to the customer (unstable consumer price).
> and supply
Oh? https://www.ctvnews.ca/atlantic/article/some-maritime-grocer..., https://economictimes.indiatimes.com/news/international/cana..., https://farmersforum.com/cracks-in-supply-management/