The British government has followed at least some scientific advice. What changed Dominic Cummings from his stance of "if some pensioners die, then too bad" when they were pursuing the "herd immunity" idea was getting a report saying that that would kill a quarter of a million people.
But they didn't heed the advice to prepare for the crisis, which is why we now need to scrabble to get hold on things like PPE, test, and ventilators. Or the advice to clamp down on it quickly and hard. Or, indeed, the advice that epidemiologists have been giving since the beginning - that the best way to control the virus and prevent mass infection is to test everybody suspected of having it, do contact tracing and test all those people, do more contact tracing and test all of those people. That's the way to wipe thing thing out quickly - find out who has it and prevent them from passing it on to anybody else. That's what worked in South Korea.
They're still not following the advice that the best thing that can be done is to test as many people as possible.
But they have finally put a lockdown in place, a week or two after they were advised to, and amidst much dithering which encouraged people not to take it seriously. And it is true that that is some scientific advice they've been given by experts.