EU is for all practical means not a single market, it's a hodge-podge of rules much more integrated in theory than in practice. Which is exactly the thing causing problems here, and ironically this is exactly what the anti-EU folks complain about. Think about this disconnect: complaining about friction and requesting less integration.

> Then you hear about Canada which has tariffs between its own provinces, but not to the US.

Canada doesn't have, and should not have, the level of ambitions the EU should have. We're talking about EU 450 million people (500+ million if the UK rejoins at some point) vs Canada 35 million.

The EU should go toe to toe with the US and China. The EU is utterly dominated by US software companies and by Chinese green tech companies (batteries, solar panels, EVs).