I'm sure this is something that a lot of people would agree with. But in case you're still on the fence about standing desks, hopefully this post will help make up your mind. I have had a standing desk for 3 years. It has changed the way I work ever since.
For one, I'm not sitting as much. That sounds obvious, but really think about how much we sit every day. Sitting while driving or riding the bus on our commutes. Sitting at the desk. Sitting in meetings. Sitting on the couch when we go home. That is a lot of sitting! After getting used to a standing desk, I don't feel as worn out at the end of the day. Just a quick search can reveal all the health benefits of a standing desk.
As developers, I'm sure we have experienced those glorious wired in sessions—when we're lucky enough to have uninterrupted time to focus on a task. When I had those sessions and got stuck on a problem, it was so easy to just sit in one place and stare at the screen for hours, giving myself a tunnel vision on the problem. With the standing desk, it became very natural for me to just walk out of the desk, take a deep breath, maybe get some water and look at the problem from a different perspective.
Another minor benefit I find with the standing desk is it's a lot easier to show someone your screen. The person doesn't have to find a chair, or awkwardly crouch. You both will just be standing!
These are just the few things that came to mind. I'm sure I have forgotten something. In the end, I believe standing desks are beneficial to developers in general. One should get a standing desk if possible. Some employers are more than happy to pay for your standing desks, too.
Edit: As some good folks on Reddit pointed out, there's one thing I forgot to mention. While it's not good to sit all day, it's also rough on your body to stand all day. If possible, get an adjustable standing desk so you can take "sitting breaks." I personally just have a high stool and keep the desk height the same.