This. After using a standing desk for a few years, I only occasionally want to sit (like 5% of the time). And I generally regret it after about 20-30 minutes.
I see a lot of standing desk users with improper monitor or keyboard height, and I think this hurts standing desks' reputation. If these are not correct, you will get neck and/or lower back pain if you use the desk long enough.
Unfortunately, it can be pricey to have a workstation that is ergonomically correct for you, because the keyboard to monitor height distance is much greater in a standing configuration vs. sitting. Convertible options tend to be expensive.
Having a cushy floor mat also makes a huge difference.
Personally, standing all day makes my feet tired & sore. I much prefer a well set-up sitting workstation and regular walking breaks.