VPNS need money to operate, and money businesses have anchors in the real, physical, brick-and-mortar world, which is ultimately under control of the British police, with their extendable batons and prison bars.

If you make money by laying asphalt on British streets and get paid in British pounds, there's no way for you to pay an internet business in Malta if the British government doesn't want you to. Sure, there's crypto, but crypto needs businesses which let it interface with the British banking system, which the UK government can instruct banks to shut down.