the conditions of the working class are also improved by imperialism
I think that’s highly debatable. If nothing else, imperialism undermines domestic labor power, as domestic workers are devalued at the industrial level and shuttled off into police/military industries where they are more easily controlled from the top. But my main focus is on the industries where democratic socialism have the biggest impact. Health care, education, mass transit, and other service-sector work isn’t easily exported and won’t directly benefit from generically “cheaper” cost of living for a functionally poorer working class cohort.
many of the stable goods consumed by the people in Scandinavia are either partially or entirely sourced in colonized countries
These consumer goods exist within the private market. Imports undermine domestic labor and retail work is almost entirely privatized. There is no notable distinction between a Swedish democratic socialist shopping at ICA and a British constitutional monarchist shopping at Tesco. They both receive the same capitalist-driven benefits. Neither system is predicated on imperially supplied imports.
people in western countries enjoy a higher standard of living because of it
People in China enjoy a comparable (sometimes superior) standard of living despite it. People outside of western countries - particularly those in the Global South - can experience democratic socialism without any of the horrors of imperialism tacked on.
Democratic socialism and imperial economic expansionism are two independent political phenomena. One does not contribute to the other, save in contradiction. I might argue that Scandinavian democratic socialism is actively being undermined by imperialist political arrangements, as in the case of Finland joining NATO and ceding a large chunk of its surplus to militarization. Alternatively, one might look at how Worst Korea, the UK, and India have suffered sever living quality declines as neoliberal economic policy cannibalizes their public sector services.
The benefits of imperialism - particularly in the wake of the 21st century - do not appear to accrue to lay residents of these nations. They are entirely bound up in aristocratic cadres who can reinvest the surplus into imperial expansion. This pattern isn’t unique to the modern moment, either. It is the same story told during the Dutch post-30-years-War Era, the post-Civil War period, and the WW1-WW2 period.
Cuba would not exploit other countries if it wasn’t embargoed because exploitation isn’t inherent in Cuban economic system as it is under capitalism.
If you showed up in Havana with a cargo ship full of H&M clothing and electronics produced in a Samsung sweatshop and cosmetics tested on adorable animals and gold jewelry mined out of a West African slave pit, plenty of Cubans would receive them happily. This is commodity fetishism in action. Nobody understands the blood and toil that made these surplus goods appear and relatively few people are able to reconcile the information with how they live their lives.
Cubans who leave the island have absolutely no compunction at consuming right alongside their American peers. Americans who visit are never turned away because their money comes from a nation full of rapacious barbarians. There is nothing inherent to the Cuban economy that prevents it from absorbing the surplus labor of their neighbors. This is entirely a consequence of US foreign policy, executed with the belief that Cuban socialism cannot exist absent the cheap labor of their neighbors.
The Americans were wrong in the 1960s and again in the late 90s when they predicted the embargo would topple the Castro government. You’re wrong now. Democratic Socialism has nothing to do with Imperialist looting and plundering.