I have a wife and kid. I have more to lose, sure, but I also have lots to gain. My friends and family who are single and childless have less of both (according to them, I'm not trying to pass any judgment here).
That's a tradeoff that is up to everyone to make for themselves, but characterizing this voluntary life path as "slavery" is disingenuous and misleading at best.
It's difficult to articulate, but I usually phrase it as something along these lines.
* As a child, relatively small things bring you true joy. Opening a toy, playing games with friends, lots of stuff. And the real version of joy, where your heart feels too big for your chest.
* After about age 20 or so, I noticed those moments becoming less and less frequent. It took more and more to grant them, things like kissing my wife for the first time, day of my marriage, etc.
* Raising my child seems to have reset this. I feel true and genuine joy almost every day, just interacting with them. It's like being a kid again, for me.
* I believe that raising my child without my wife would not be the same experience, and probably would not give me the happiness I have now. She has expressed all of this to me as well.
That is what my current life path offers me that a hypothetical single me would not have had, and it means an awful lot to me. This is obviously not going to be true for everyone, but I also don't imagine I'm the only one who feels this way. The above is almost a cliche, it's voiced so often.
Obviously there are also tons of stats about life expectancy, average earnings, and other such economic and practical metrics being better for married men in the USA. Those are probably true to a degree, but don't resonate with me the same way. Plus, this being HN, I imagine a lot of us would be fine either way.