Know-How Exchange : Advertising/PR

ERGONOMIC ==> an applied science concerned with designing and arranging things people use so that the people and things interact most efficiently and safely.

Nothing is "wrong" with traditional furniture, but "traditional" may sacrifice safety and/or efficiency in order to deliver certain aesthetic benefits, or to save production time/money.

How is this a marketing question?

When designing ergonomic furniture, it is necessary to take into account anatomy, the structure of the human body, the location of muscles as well as medical indicators to prevent various diseases of the spine, respiratory tract, etc. Materials should be non-toxic and light, but proportionate to the size of the human body.
It is mainly aimed at office space, educational and public institutions, but in recent years the market has significantly expanded to households (especially with the growth of the home office jobs), and of course there's a constantly growing market of ergonomic gaming furniture for teenagers.

Ergonomic chairs are designed in such a way that they match the natural curve of our back and hence provide very good cushion to the lumbar region of the spine. So even if you have to spend long hours sitting in the chair, you won't feel back pain. This is the advantage of ergonomic chair over normal chair.