Other comments in this thread make it sound like an absolute nightmare. So which is it?
It's only a nightmare if you hate all taxes and labour rights. So, you know, YC
Since this is purely about ownership structure and equity governing law, I'm curious what the intersection you're seeing between these terms and "labour rights" are. We're a US company with employees in Europe (not even an HQ in Europe, just employees there), and I've learned more about European labor law idiosyncracies over the last few years than over the whole rest of my career, because I've had to.
It's complicated. In theory, US states have more rights and powers ("The powers not delegated to the United States [...] are reserved to the States" [0]), but in practice, the Commerce Clause lets the Federal government do essentially anything that it wants. Canada's provinces are only given control over a specific set of topics [1], but their powers are almost absolute in these areas, since the courts almost never let the Federal government interfere.
So for labour code specifically, US companies need to adhere to both Federal and state labour codes, while Canadian companies only need to follow a single provincial labour code. (There is a Canadian Federal labour code, but that only applies to Federally-regulated companies, and those companies don't need to follow the provincial labour codes)
[0]: https://en.wikipedia.org/wiki/Tenth_Amendment_to_the_United_...
[1]: https://en.wikipedia.org/wiki/Constitution_Act,_1867#Part_VI...