Surprised nobody has brought this up yet. There is also a competitive element to family additions in the form of pets. While not cheap, they are significantly cheaper. Lower emotional and financial stakes also makes them feel like an easier choice.

"Loving dogs has become an expression not of loneliness but of how unhappy many Americans are with society and other people. [...] For some owners, dogs simply offer more satisfying relationships than other people do." [0]

[0] https://theconversation.com/americans-are-asking-too-much-of...