90% of all covid-19 deaths in Sweden have been people over the age of 70 [1] which is the only group of the population which have been quarantined. So it's arguable what difference a nation wide quarantine would have made.

Of those over 70, half of the deaths were in care homes and another 26% had home care [2].

Many of the workers in care homes have reported that their companies/bosses won't allow them to stay home when they're showing symptoms and some have been forced to work without protective equipment.

There have "only" been 42 deaths under the age of 50 [2].

[1] https://www.svd.se/90-procent-av-alla-doda-i-covid-19-over-7... [2] https://www.svt.se/nyheter/inrikes/halften-av-alla-doda-over...