[1] https://www.affarsvarlden.se/juridik_affarer/facken-stoppar-... (Swedish)
Why is this?
It's not quite clear why anyone thinks that. As far as I know Sweden has a pretty typical welfare state and union laws, comparable to the UK. It's a very politically left society in general with respect to things like identity politics, but economically it's not much different to France or the UK or other countries with publicly funded healthcare.
Economically in those countries and much of central Europe (notably Germany), large old companies, their unions and government are merged to some extent or at least highly cooperative. The result is a sort of company based welfarism in exchange for incumbent protection. Good and bad aspects to that, but it takes a lot of stress out of the system. It's very hard to fire people. It's also hard to build new large companies.
I'm not sure if the system is transferable elsewhere or even buildable if it doesn't already exist. You can't just conjure up a Siemens.
It's certainly not Marxist, itd probably be classed as right wing structurally if we go by the terms of the late 19th.