Because.... they never had a national shut down, they never closed all their pubs, restaurants, bars and businesses. They never closed all their schools and education facilities.
They never insisted on everyone wearing masks and they still don't.
They currently have all their public services and transports running, over 90-95% of commuters do not wear masks.
They DID have a limit on outside gatherings... No more than 50, yes 50 people are allowed to gather. They do ask people to observe social distancing, and wherever possible people do.
Like it or not, argue population densities or whatever you like, their economy is in much better shape than ours.
Go to Sweden tonight and you will find all the pubs open and people out socialising.
It's debateable as to whether the Swedish population are more or less at risk than the UK, but what is true is they have had less deaths per 100,000 of the population and, last time I checked, their 14 day reinfection count was miles below us.
Which model would I choose to follow, Swedish for me, you are quite entitled to disagree.