You could really ask this question of anyone about anything. There will always be substantial differences between one person's life and another. Having had children doesn't necessarily denote that difference, even less so for men as some fathers don't stick around and instead go live their own lives seemingly uninterrupted.
But think of how many things people sink great amounts of time and effort into; gambling, becoming a practicing doctor, hedge fund trading, starting a charity, programming... Those people will probably all have large amounts of time devoted to those things.
Of course there'll be many things that don't compare, and some that do... Then you must also factor in that it's a trauma for some people. Some people end up not liking their children, kicking them out, disconnecting.
Human nature is hugely variable. What's it like being a good person? What's it like being rich? What's it like being homeless and a drug addict? What's ut like being happy? What's it like in prison? What's it like as mayor? Or psychiatrist? Or teacher?
What's it like not like doing any of the things mentioned here? Well, that question, your post, is really about you, isn't it? It's about you asking others "what would my life be if I didn't, or don't have kids?"
Because it's not a bad thing to ask another person about their experiences in life. And putting it within the context of a particular life choice adds a layer of focus to the conversation.
Given your logic, no one should ever ask anyone else any question about their personal experiences other than to retrieve information.
putting it within the context of a particular life choice adds a layer of focus to the conversation.
It won't create a very interesting debate though, because OP already excluded most people who followed through on the opposing view in the question itself.
This extra layer of focus really functions as a filter, which can only result in a hall of mirrors.
It's perfectly fine if OP just wanted to confirm an existing bias and need arguments for that, but it's absolutely not a very interesting conversation.