We have one kid. I never really saw myself as a dad, and was also indecisive when the wife first started pushing the issue. Of course I love the kid to death and have a ton of fun with him now that we have him. I am also glad we only have one. But that is not the real question. Would I be better off, happier, healthier, more fulfilled, richer, etc without a kid?
Happiness: A wash. I have had to scale way back on all of my favorite things like rock climbing, backpacking, sewing, and other hobbies because I have very little "me" time. The kid brings a different kind of happiness, but I wouldn't say I am significantly more or less happy than if we had just one. Lazy mornings and evenings have been replaced by early wake up calls of a kid climbing up into our bed, making breakfast, immediate requests to play when arriving home, bath time, book time, changing into jammies, and finally bedtime. If I am lucky I get my first "me" time at about 9 PM when I already feel exhausted.
Health: Worse. Less time to work out, and an even smaller overlap Venn diagram of food choices for the house makes meal time and cooking a modest point of frustration. More frequently than I would like to admit we resort to Mac & Cheese or other slam dunk kid friendly choices rather than cooking good stuff that is complained about, not eaten, followed by a hunger driven rough evening battling at the snack scrimmage line. After age 2 I was much more able to resume better activities, and bike 7.5 miles to work every day, but it is major effort to get close to the activity level I was typically at 5 years ago.
Financial: Worse, obviously. Wife is stay at home, and never got off the ground trying to become a teacher (bad timing, then kid). She would have been pulling in ~$40k as a teacher. Kid is an extra drag of $10k a year, easily, for food, clothes, classes, gifts, trips, etc. I also have had to outsource more house work than before. Less spare time means less time to mend fences and paint the house myself.
Fulfillment: Better. Not sure how to say it, but seeing a little kid blossom in part due to your parenting efforts is very fulfilling and at least feels like it makes up for a lot of the crappy stuff.
Risks: Some kids just suck. Most can be parented into becoming fantastic adults. But being a pragmatic engineer I will say that there are plenty of kids that take tons of extra effort, are stubborn, learn the hard way, lack common sense, are naturally mean or bullies, lack empathy, etc. So while our kid has been pretty easy going with a great personality, it is a huge crap shoot. Will you being willing to risk a kid with major medical issues, mental issues, or who just happens to have a really difficult personality? Look around at how much "fun" a lot of parents have through the teenage years and make sure you are ready for 5-6 years of being yelled at and hated for doing your level best.
I will say that it was very useful to have candid conversations as to how I was feeling about having kids, about parenting philosophies, finances, etc before we had the kid. Many of those discussions have been overridden by events, but it really made us part of a team going into it. In part it sobered up my wife as to some of the difficult realities of child rearing that she was glossing over all too easily.