I'm a dad, too. The lopsidedness could come from many places: mothers being drawn to parenting websites (marketing), women feeling more compelled to voice complaints online (if they are stay-at-home-moms, they don't have coworkers to chat with), women actually getting treated unfairly (very true... patriarchy), etc.

I've heard this from many moms, "My husband does so little in terms of housework, childcare, play and mental load, that it is actually easier when he is out of the house; when he is home, I essentially have to take care of an additional child." I even know some moms that organize playdates for their husband, as in ONLY the husbands, so that that the husbands are out of the house.

On the other hand, I know of two separate marriages that fell apart because the husband worked, did all the child care and housework, while the mom stayed home and doomscrolled. After a few years of no improvement, divorce. Of course many things could be at play here... screen addiction, post-partum depression, etc.

Raising kids is complex, time-consuming, hard, and amazing. It takes a lot of energy, people, and love. I always try to assume people are doing their best, though sometimes even that's tough.