Ah, Denmark. Good ole Denmark. A country of 6 million homogeneous people where 87% of the population have descended from the same group of people for the last 12,000 years. Are we sure that much of their success doesn't extend from overwhelming common cultural values, some of the strictest immigration laws in the world, a homogenous population structure, and a general lack of an urban class cluster bomb that extends back to the Gilded Age?
I've always found comparisons to the Nordic countries and their economic/social systems to be the equivalent of someone comparing the teaching successes of a teacher (Nordic country system advocates) who runs a homeschool co-op with 6 kids from an affluent family structure giving condescending tips to an urban US teacher (US educational reality) who has a packed-out class with 36 students, half of whom have special education accommodations, while doing it as one teacher without even a paraprofessional to assist them.
Yes there are things we can learn from countries like Denmark, but from an institutional level, it's like comparing that homeschool co-op to the urban class and saying, "we can do that too if we just try harder and create better policies."
No we can't. Not until the desire for "urban renewal" is preceded with an American society that stops making excuses for inequality and starts prioritizing domestic accountability in terms of how we raise our children. Even if we had an entire culutural shift in terms of maximizing these priorities, I still think it would take two to three generations to cleanse our society of the old "who will save me" mindset that plagues the urban areas.
It doesn't look like we as a society are very interested in any of that. In fact, "the academy", and whatever is left of its soul, has made it their mission to crucify individuals like Booker T. Washington over the last 60 years merely because he prioritized self-accomplishment. Little wonder that urban education and poverty have maintained a bottom of the barrel status in that same span.
So since our supposed "leading academic minds" continue to drink the policy-as-salvation Kool-Aid instead of pushing all their chips in on individual work as the core principle of self advancement, I think we're cooked at the moment. Systems aren't going to change whether little Johnny goes to bed before 1 AM on a school night or whether or not he's eating a steady diet of Takis, french fries and Mountain Dew. That comes down to value priorities, and the urban value system is largely inadequate.
See also: Japan, Canada, Australia, China, France, UK, South Korea as countries with a lower Gini coefficient (measures income inequality). https://ourworldindata.org/grapher/gini-coefficient-wb?survey_comparability=no_spells
The US scores relatively poorly. The "work hard and pull yourself up by your bootstraps" came from the 19th century as a sarcastic joke about an impossible task. We all live and work within some type of system, and that system should work for the most amount of people possible if our goal increase the well-being of many over a few. Individual work and social systems are not incompatible. In many countries, social systems actually help them become more independent and give them the confidence to work hard, relying less on others.
For example, in the US people often live with their parents into their early 20's and move back in with their children later in life. This places a huge burden on individuals on both ends of this to have to take care of those we love leaving not much room for an authentic relationship with them. Many countries flip this through social systems. These systems intentionally free individuals from structured dependency on family members and employers. Universal Healthcare and free education can be viewed as creating a launchpad for personal liberty instead of a "nanny state". Having lived in Denmark I can confirm. I lived in their system and it's fantastic compared to the US. Yes, they pay high taxes. But by the time you account for what Americans pay into employer based programs and our lacking social systems, it's actually closer than you'd think. Yet they have higher level's of transparency, removing unnecessary layers of underwriters and companies seeking to make a profit off your well-being. And these other countries do this while having a higher economic freedom than the US. There's a lot we can learn.
None of this is to say that these other countries have everything figured out. There are very good counter points, as you mentioned. But I think people overall in the US have a very closed mind to social systems. Powerful people in the US with money and influence have run programs for years in rural areas to encourage the masses to think social systems are freedom takers, and not freedom givers. This has left Americans very ignorant to other ways of life. Now, many times a rural American sees a different way of doing things, they simply parrot what they've been told. I encourage people to travel if they can, and remain open minded about other ways of living than straight up capitalism. Personally, I love capitalism. It is partly responsible for the biggest uplift of people out of poverty in the world and has created countless amazing technologies. But I can also appreciate that there are social systems that when combined with capitalism create a balance that is best for the largest number of people, instead of the few that are already rich and powerful.