Disadvantage of ergonomics?

Answer 1

The main problem that ergonomic equipments  are perceived as having is that getting used to them usually takes time and effort. Though once you get used to it, it can make life easier, faster and less awkward, but getting used to it can take time and can cause error and frustration when you are doing so. One does need to practice before one can become used to it and regain speed and error free work.
The disadvantage is that ergonomic items cost more.