I guess this is pretty much already expected for UK is having a hard time dealing with their infected cases and keeping up with their economy. Might as well do such restrictions to slow down the increase of the cases so that they can work out dealing on how to settle things out with regards to their health and economy for both are important and no one must be set aside nor be compromised. Actually other countries have already done border restrictions even my country does that on the first months of the pandemic to prevent potential carriers to come through coming from foreign countries and have those individuals to quarantine on our isolation facilities to check them up before they have been released home.