Spoilers, I guess, but it IS in the title.
This break up seems to be based on him (Doug?) needing to progress a 10-year relationship by getting married, buying a house, and having kids while she was content with how things were. From what I gathered, she is a barista, he is a copyeditor, and they live in Portland--where the cost of living has increased astronomically.
This was such a missed opportunity--write about how 30-year-olds cannot consider homeownership and having children because wages are stunted. Write about how easy it is for the 30-year-old crowd to underperform and give up. So many directions this should have taken and it was disappointing and cliche, with a decent dose of woman-blaming.