1) The EU is in severe decline. In 2000, the US and EU had economies that were roughly the same size (the EU's was actually a little bigger). Now the US economy is 40% larger.
Put another way, 30 years ago, the EU had about 25% of the entire world's GDP. Now it has about 14-15%. 30 years ago the US had about 25% of global GDP. It now has about 26% of global GDP.
The EU's economic heart, Germany, is in severe decline. Due to idiotic Gaia worship driving energy costs to stratospheric levels, Germany is rapidly deindustrializing.
This is what Carney proposes hitching Canada's wagon to.
2) Does he really think the Europeans would choose Canada over the US given its economy is only 1/13th the size and given that Canada is neither a dominant player in high tech nor does Europe rely on Canada for its defense - unlike the US? Sure, they may love the open borders globalism and the Gaia Worship (which is killing Canada's economy) but....get real. They are fully aware which side their bread is buttered on.
3) Distance is a thing. Sorry. Hate to break it to you, but distance still very much matters. The US is right next door. The EU is an ocean away. The logistics are never going to make nearly as much sense for Canada trying to trade more with the EU and less with the US.
This antagonism toward the US will work for him right up to the point that Canadians really start to suffer - which is going to happen bigtime in a few months.