Tesco's and Sainsbury's have improved a lot, if they say they are supporting mask wearing and covid measures then presumably they plan to keep things that way.
Actually, I think I read that Sainsbury’s are removing some of the other covid measures, such as screens between the self-checkout tills, and between queues at regular tills. They’re keeping the ones between the cashier and customer though (it may have been Tesco I read this about, but I think it was Sainsbury’s).