As I'm cynical the reason I believe EAP/FSD isn't available on subscription here (or Europe) is because if it were it would expose more people to the cold, hard reality of it being almost completely worthless.
As it is the barrier to entry is so high that anyone actually buying it is either a true believer in Elon/Tesla who believes FSD in the UK is on the horizon, or is just unfortunate enough to have taken "Upcoming" on the order page to mean a practicably soon period of time, not several years away.
At least those of us dumb enough to have spunked £3,400 - £6,800 on it are just a silent minority who have to individually take Tesla to court to get their money back. The wider world doesn't know we exist.