Ah sorry, you're indeed right. Turns out it was just the .service.gov.uk domain that uses GCP and AWS - I just thought that applied to the parent domain too.

Ah sorry, you're indeed right. Turns out it was just the .service.gov.uk domain that uses GCP and AWS - I just thought that applied to the parent domain too. $ dig NS service.gov.uk +short ns-cloud-e4.googledomains.com. ns-cloud-e3.googledomains.com. ns-cloud-e2.googledomains.com. ns-cloud-e1.googledomains.com. ns-831.awsdns-39.net. ns-1983.awsdns-55.co.uk. ns-117.awsdns-14.com. ns-1080.awsdns-07.org.