Yeah, the only problem with that is there's nothing stopping you from taking indirect flights into the UK.
I'm currently in South Africa, which had its own virus variation that entered the UK a month ago, resulting in a ban on flights coming directly from SA to the UK, However, indirect flights are still permissible, subject to satisfactory PCR testing.
So this coming Saturday, I won't be allowed to fly from Johannesburg to Heathrow, but i will be able to fly from J'burg to Schiphol airport in Holland, and then onto Heathrow, London
So what's the point?