Earlier quoted context omitted.
I'm not pretty sure about that. I get cookie banners from US companies all the time and choose to reject them. Just visited www.vmware.com. Site is located in the US. Company is located in USA, and OneTrust's cookie banner welcomed me, and allows me to make choices.
VMware wants to sell to European clients. If they didn’t they wouldn’t have cookie banners.
a) Show the cookie banners if somebody is coming from a GPDR or GDPR-compliant country, since it's required by EU law and these GPDR-compliant laws.
b) You geofence your site and prevent access.
So, in practice regardless you whether sell anything or not, if your site, proverbially, touches European soil, you have to show these choices.