I have a kid with my partner and I'm still not sure it was the right decision for me. They do become a full-time job in their own right and there is a whole set of skills that you can kind of learn through books but is going to be unique to your little one.
The first couple of months were especially hard as they don't have much of a personality, don't really react much to the world around them, they're just feeding, sleeping, and growing. Starting at the beginning of the third month for me it started changing and every baby is kind of unique.
I now _detest_ most of the books/articles/child-rearing advice I've encountered. Most of all of their content is fluff to pad pages, a blog roll, and are frequently superseded by more modern research backed evidence. There is a lot of toxic advice in those books and systems as well, usually for parents that are prioritizing restoring their prior social lives over the well-being of their children.
It's time-consuming and exhausting, but I haven't found it to be _hard_ yet. Waking up in the middle of the night and giving your kid a hug and maybe reading to them a bit when they have a nightmare isn't a challenging task. The challenging tasks are exceptions (surprise medical issues, your daycare closing down with two days notice, etc). The baby and child industry put a cost premium on the clothes targeting them and they don't last very long due to the child's growth. I _saw_ this coming but not to the extreme it has actually manifested and you'll find it replicated in every child/baby sized item.
There are a lot of surprising upsides and my motivations have definitely changed since we had a kid. I will flip a mountain to see my kid smile and laugh, it hits deep. I enjoy spending time with her and I'm terrified of missing her achievements and milestones. When she comes to me and asks me to show her how something works, wants a book read to her, or just wants a hive five I get a double whammy of that serotonin once for being a Dad that she wants to engage with and once for getting to spend time with her.
I still, and unfortunately kind of frequently, miss what I have effectively sacrificed to have her. I am slower at staying on top of emerging trends, hobbies have been left by the wayside that I did for decades, I gave up running conferences and with it I drifted away from whole treasured social groups. None of this was really a surprise, but I didn't realize how much what I gave up was really part of who I was.