I don't really disagree that this is a problem in and of itself, but aren't we at a historically high level of young people living with their parents?
Historically high? definitely not.
The highest since the 1950s or so? Maybe. But before WWII it wasn't too common for people to live independently before marriage.
Before WWII it was uncommon for young people to go to college and obtain degrees that would take them far from home, professionally.
Before World War I was uncommon for young people to go to college period.
Beyond that, you are making the same mistake most conservatives do and you're stupid and interchanging cause-and-effect.. The breakdown of middle class economic economic support has broken down by the family. Loss of middle class paying Union jobs has made many young men frankly unmarriageable. It started in black communities with the advent of deindustrialization, then went through other communities of color just as readily, And finally then with Appalachian and poorer white communities, and now into the "traditionally middle class" white community.
If you want to reverse it, OSR comments gonna take a lot more than tisk tisking more than tisk tisking and finger wagging from right wing intellectual is, but a fundamental rechanging of the economy and ways that would be utterly abhorrent to you and yours.
So you're saying that someone who is poor is not worthy to marry? Or are you saying that all potential brides are money-grubbers?
Two people who graduate high school, get married, go to work, and keep their jobs are far, far more likely to have functional (and reasonably happy) families than people who have children out of wedlock. The outcomes for children in terms of stability of income, educational achievement, and pro-social behavior and interactions are all better. There are many reasons for this, but the basic reason is that the most significant determinant of a child's happiness is the condition of the relationship between the two (2) parents.