The local culture makes French and German unions very different from US and UK unions. The former are wise enough not to kill the golden goose, the latter can't see any further than Christmas.
My limited understanding of US unions was that the ones which augured companies into the ground had a toxic, dysfunctional, non-communicative relationship with company management. Even when the company management was sharing and showing them the books and the mathematical certainty of everything shutting down if changes weren't made, the unions thought the company management was pulling the wool over their eyes. So they decided to call what they felt was company management's bluff, and called it wrong.
I've never felt comfortable with the narrative that these particular US unions were so short-sighted they would cut their noses off to spite their face; that doesn't fit the prior narrative of the enormous amount of diligent, persistent work it took to organize in the first place. I'm more inclined to believe the narrative that there was such an antagonistic, distrustful, hostile atmosphere in those meetings that union and company management were together as doomed as a Greek tragedy.
Any US union history buffs out there care to clarify what the current thoughts are here on what really happened?
From that history, American Unions have almost always believed that the government and the business owners were out to get them. Also, because the Southern American states have historically been the most anti-union, American corporations have had a much easier time moving from union friendly areas to anti-union areas then European companies.
So, overall union-business relationships in the USA are much much worse then in Germany. American businesses routinely make decisions solely to hurt unions (a good modern example is Boeing which is moving production from Washington to North Carolina, a large part of which is about weakening the union, even though this has made logistics harder), American unions think of management as the deadly enemy.
I think a model more like Germany's where Unions and Businesses tend to work together would be overall much better for both sides, but we're stuck in the current system. It's also not helped that now there is a strong political anti-union movement no matter what the situation (like when Volkswagen wanted to unionize their plant in Kentucky in order to practice business on a more German model local politicians and businesses were strongly opposed even though the actual managers wanted it).
It would even be beneficial to let small business owners unionize against larger companies.
Imagine how much the economy and small business owners, say gas station owners, could benefit if they all unionized and could collectively bargain against Shell, and could collectively set the wage/prices they sell gas.
One can dream...
because you've basically just described what they call a "trust" when they make antitrust legislation.
(Alternatively, you've described the National Industrial Recovery Act of 1933, later found unconstitutional - leading to FDR's infamous court-packing attempt - and considered by a little under half of economists to have been a major contributing factor which prolonged the Great Depression.)
Getting more power to ordinary workers is laudable when it comes at the expense of the power of their large-corporation employers... not if it comes at the expense of everyone else in the economy.