If your startup is selling to US government, sure, but otherwise I don't think there is much unreliability in selling SaaS, courses, or whatever gadget to US residents?
We will get Greenland one way or another. That's a horrid statement if you are Danish (and worse if you live on that island). Realistically it's a horrid statement, anyways.
From a UK perspective (and I'm not a CEO or anything) it looks pretty volatile over there. Tariffs, radical changes to government funding, widespread corporate overhauls... . Predictability is surely desirable when considering dependencies.
If you depend on the US for defense, and the USA says that the victim should just surrender, there's a risk the same might happen to you. It's quite black and white in this case.