Why co-ops aren't Socialism (At least under a Capitalist system)

Socialism is commonly defined as the ownership of the means of production by the proletariat. In theory, co-ops are Socialist, because the workers have democratic control over their workplace, and they own their workplace (which is why I've erroneously used them as an example to explain the rationality of collective ownership in the past).

However, they fail the test of rejecting Capitalism, because they still have interests in supporting the Capitalist system. While workers get to keep the profits, they still need to compete with other businesses. This means they are incentivized to give themselves similar income, though it remains more efficient because they do not have shareholder shackles which means that a higher margin of profit can remain as retained profits to be reinvested into the business and competing.

Continuing this line of thinking, they are disincentivized to invest in vertical integration because this would hurt their own material interests. Co-ops in the age of imperialism are materially interested in exploiting cheap labor in the imperial periphery; miners in the Congo, factory workers in Bangladesh, etc. rather than vertically integrating necessary business processes/sectors, because that would mean sharing a "slice of the pie" with labor they can get for cheap.

This also makes revolutionary Socialism; inherently opposed to imperialism against co-op interests as co-op workers are effectively petty bourgeois, against co-op interests. Co-op owners take home less money, less profit if they stop benefitting from imperialism. Naturally, in any principle contradiction between Socialists and Capitalists, co-op owners will side with Capitalists every time. The only material conditions where co-op owners would side with the left instead of the right is when imperialist tendency toward monopolism intensifies to the point where co-ops no longer benefit from imperialism and are instead out-competed, as they fall behind on producing labor at the socially necessary labor-time by failing to be able to invest in capital the same way larger imperialist corporations afford to. whether you agree on LTV or not, falling behind on SNLT means that either its more difficult to supply at demand, causing either higher prices and out-competition, or lower profit for co-op owners. If you are more convinced by marginal theory, each co-op owner provides less marginal productivity than the workers of big corporations if they "fall behind SNLT" if they have less advanced capital. Even in this situation, however, they could just sell out to the big corporation and still benefit from imperialism, and essentially remain as a part of the labor aristocracy. On a similar line of logic, unions in the imperial core are also materially interested in imperialism, as they can secure better pay for domestic workers (at the expense of workers in the imperial periphery) through uplifting union members to the status of labor aristocracy through appropriating imperialist super-profits toward union members' wages. We can also see empirically that the US' major unions support imperialism.

The only true Socialism is a collectivized ownership of production, where the majority of enterprises are socially owned by the proletariat as a whole, and the workers most materially interested in true Socialism come from the imperial periphery, not the labor aristocrats and petty bourgeoisie in the imperial core. While co-ops could exist in a Socialistic manner under Socialism itself, under Capitalism they are materially interested in reproducing Capitalist and particularly imperialist conditions. Socialism through co-op'ing is just a petty bourgeois fantasy and is "not true socialism!". This goes to both liberals who tell the left to "practice what they preach" as well as the likes of social libertarians or market socialists who erroneously assume that simply strengthening unions and co-ops makes for praxis.