The same issue applies with family unit wage earning and has probably been discussed elsewhere with regard to the gig economy:
If an individual family decides to have both parents work, they begin to reap the benefits of two incomes, with the few added costs of such a choice, like childcare, transportation cost increase, etc. Overall, however, they have an advantage over all the families who are single-earner households. That is, until everyone in a local economy does that, then housing and other goods inflate.
I believe it was on a previous discussion about these businesses that I saw someone draw the same conclusion about the gig economy: people working another side job, in addition to both spouses working, get an advantage, only so long as everyone else isn't doing something similar.
The end result, either way, is that prices inflate, and people are working even harder to stay afloat. Especially if they made poor economic decisions to earn that extra income (paying exorbitant childcare costs, or incurring more in vehicle expenses than they earn from driving).