For me, it’s primarily an ethical concern, and I’ve never even attempted dating someone I met at work. I think it can work, perhaps as well or better than meeting in other random ways because at least you two share that in common. That means maybe you have common interests, or at least you can commiserate about whatever happens there. Then again, meeting someone at the gym, church, a concert, or wherever likely means you share that in common, so that doesn’t really mean a whole lot unless you met someone in a place where there isn’t commonality, like at the grocery store or a dating website. So, I dunno.
However, back to my ethical concerns, I see two major issues. First, and most obviously, if things don’t work out, particularly if it ends awkwardly or badly, it not only damages the ability for the two of us to work well together, but can create issues for others, either just feeling uncomfortable or gossip or whatever. Hell, even if it ends neutral or amicably, if the office is large enough, there’s bound to be some rumors or other random things that can cause problems.
The second issue is, if it works out well, do we have the ability to control for our emotions and still treat eachother appropriately at work. I’d like to believe I’m capable of that, and I think I’ve generally succeeded in the past of not showing favoritism to people I like, but I really can’t be absolutely sure. If something does come up where we have to butt heads, either as part of our jobs or because we disagree, it will be difficult for even the most mature people not to feel a little personally hurt. And even if the two of us are absolutely able to make that life/work separation, I doubt that everyone around us can. Confirmation bias could very well set in that, if I were to take her side or her mine, someone else could easily assume it’s because of favoritism, and we’d both have to work that much harder to back up our decisions and actions. And, again, in a large enough office, rumor mills can be poisonous to everyone.
So, sure, it can work, but there’s definitely some major obstacles that just wouldn’t exist if you’d met somewhere else. That said, I don’t think it’s necessarily the worst thing in the world, just keep those things in mind. Do not let work and personal life bleed into each other, others at work just generally don’t need to know. If things do start to get serious, to avoid even the appearance of impropriety, make sure you have minimal direct interaction, even if that means one of you requests changes in duties, a transfer to another department, or even start looking for another job. When I HAVE seen couples that work together, they always were in different departments. They could still drive to/from work together, have lunch together, even chat on and off through the day and all that, but they dodged the vast majority of the pitfalls.