I don't think I can answer that :-)
I think the GDPR applies to any company providing services to an EU citizen, regardless of where it is. So I guess that means yes to your question? Does it mean you can force foreign companies into becoming compliant by using their services unless the actively block EU citizens from using their services?
I guess that if you started using that service knowing that it was non-compliant, we could say you were implicitly giving up that right, but I don't think that is something you can do individually given that it's a right affecting all EU citizens.
But, honestly, now I am talking about things very out of my area of expertise :-)