There are a lot of details that distinguish defined benefit pension plans. One is if the pension is promised by a federal government that can print money, so Sweden's pension would have to be compared to the US Federal government's pension.
https://www.aei.org/wp-content/uploads/2018/03/Automatic-Adj...
Sweden actually just made some great changes to their pension system, and in fact it's no longer a defined benefit plan in the traditional sense, so your benefit is not guaranteed (aka defined). Sweden went ahead and said we're not giving you any promises, and pension payments will be adjusted on an ongoing basis due to demographic and investment return changes.
On the other hand, you have state level and local governments in the United States that have traditional defined benefit pensions (you get at least $x based on this formula, frequently with a built in cost of living increase). Not only that, but some governments baked this into their constitution, so there's no way for these to be reduced. And state and local US governments can't print money, so they only have two options: cut costs and raise taxes.
On top of the above, there are perverse incentives for the people who set the pension benefits. Obviously, the union workers want the most they can get. The politicians need union votes to get elected (everyone in the union votes, but most Americans don't vote in local/state elections). So politicians can choose whichever actuary uses the most liberal assumptions to make the costs seem lower than they are, the unions vote for them, but of course the contributions to the pension fund to ensure these benefits is NOT required. So politicians can also choose to forego them, which they did and leave it for future generations.