Well, it depends on the kid, the time frame, financial situations, partner involvement or not and what kind, what sorr of things you enjoy, etc.
You mentioned reading. Not everyone likes to read. Even if you do, if you have an overly fussy or unhealthy kid, you may not be able to.
What if your favorite hobby is riding motorcycles? Not everyone has hobbies you can carry a baby along with. You can wrench, but without someone to watch the baby a while you're not riding anymore.
There's also the fact that some stages of children's lives are just boring or wearing for the primary caregiver. I think bouts of monotony are normal and natural, especially for types who don't do well with overly regimented routines. Some babies require that or they scream all the time.
I got lucky. My daughter was easy and I could keep her with me for anything I wanted to do. I read a lot, taught myself programming, went to the pool a lot, started writing again, trick trained our hamsters, etc.
But I gave up my career ambitions, going back for a PhD, backpacking, shooting, my male friends bailed, and a lot odnother stuff.
It changes my life more than I could have imagined. I think we need to be real about that. The first part of your essay came off as a little shaming to me, like if you're bored, it's your fault. It would have been more accurate to acknowkedge that at some point as a mom or primary caregiver you're likely going to experience some boredom. Not all the changes that come with being a parent are ones you would have chosen for yourself or ever even thought you were signing up for. It helps to keep open mind about your options but that's not always easy or apparent when you're in the thick of it, you know?
You were right about the devaluation of women's work. You can track it alongside industrialization.