The US is not so bad for certain ethnicities - some are just slanting the numbers.
One of the things you have to realize is that if there is a lack of welfare, divorce and alimony-systems, then the divorce rate goes down tremendously and women only leave men when the guy beats the living hell ouf of them - and even then they often stay.
In Germany I know that the single-mother stats of mixed marriages with African fathers is close to 90% - it's almost all across Europe. I noted the same issue with a few mixed friends from other countries - always the missing father and the single mother. Depending on the social strata and support that kid can turn out fine, but the family structure does not look so good.
The interesting aspect is that people point to African countries as beacons of stable marriages. If you implemented the Western welfare and alimony support system, then we can safely assume that it would go the same trajectory as in the US. Some places have single motherhood stats of 20% while having close to zero welfare and divorce laws - we could imagine that rate to be 30-40% if modern Western systems were implemented. A similar reduction of single mothers would happen if suddenly welfare ran dry, both men and women had to work or welfare was suddenly tied by the law to having a married father in the house.
Some tribes just react to dysgenic incentives less - Asians beating Whites easily in the US is no surprise there. Latinos follow the same trajectory - somewhat more stable in Mexico, but cross the border to the US - poof 300% more single mothers quickly. There is far less financial safety in order to do this.
In order to compare stats we would have to look at countries with similar welfare and divorce systems.
Another point is that some European countries have a high co-habitation rate vs marriage rate. So many children live with 2 parents even if they are not married, they have stable relationships. High-trust higher-IQ societies also don't collapse into eternal riots, knock-out games and mass-crime waves only because 18% of the kids are raised by single moms - out of those another 10% are either never-married or live with a stable partner/second man as well.
The assumption among many metrics is that single-motherhood = creates high level of dysfunction, when we have to take a look at the data cleaned up by ethnicity and other countries as well. If places like Hungary with a 21% single motherhood ratio are not lawless ghettos, but many US areas are, then something else may be at play. You could send your daughter hitchhiking all across Hungary and almost anywhere except the few gypsy areas, but I would not recommend this in other countries now. Sweden pre mass migration also had a high divorce rate and relatively high single motherhood ratio - they still were a high-trust low-crime country according to all metrics. There simply wasn't the shame with divorce and single moms associated as in countries like Japan which keeps the rate low.