Pensions probably ought to be reduced/readjusted in accordance with life time expectancy, or some other maths that actually ends up in the green somehow while still allowing those who cannot take care of themselves to live a decent life. I've seen enough rich pensioners (my own grandmother among them...) to come to that conclusion.
The US spends an inordinate amount on healthcare since the system is covered in leeches (17~% of GDP compared to 10~ in Europe).[1] If a significant part of US debt is caused by healthcare costs, then that sounds like a political own-goal. That's not to say the costs in Europe are insignificant. We can probably do better here too.
[1] https://jamanetwork.com/journals/jama/article-abstract/26746...
The US healthcare system is incredible compared to socialized systems if you can afford it. That's at least part of the reason it represents 17% of GDP. The same procedure I needed had a 2 day wait time in the US and a 10 month wait time in Canada.