There is no way for both parents to be "authentic self" while the kid is small. Whether it is one of them working many hours a day whole the other says home or whether it is both juggling work and parenting.Something gotta give. The time you was being "authentic self", whatever it means, is the time that is now spent supervising toddler.
Sometimes one of partners remains authentic self and keeps all those self things. And it looks cool until you realize their partner is not getting any "me time" at all or help. And that setup is significantly less cool for partner.
Sure, but balancing the needs of multiple people is what a relationship is all about, and the idea that you give up on that entirely to focus solely on your children what's being criticised here. Yes, your children will have needs, and yes, you will need to sacrifice some things to help your children, but that doesn't mean that "your life is no longer your own", any more than the sacrifices you make to form a relationship with a partner.
To be charitable, I think the original post was more making an argument against complete individualism, and I broadly agree with that in principle: if you live in a community, you will have to deal with compromises between what you want and what other people want. But it's dangerous to push things too far the other way: if you are making all the compromises, and getting nothing that you want, then there is something unhealthy about that relationship. Obviously that plays out differently for relationships between adults, and relationships between parents and their children - you can't sit down with a baby and set clear boundaries! But making time for yourself, and organising things so your needs are met is still important.
Sometimes one of partners remains authentic self and keeps all those self things. And it looks cool until you realize their partner is not getting any "me time" at all or help. And that setup is significantly less cool for partner.