People first or Design first?

I have spoken to my friend who is an industrial designer about designing a chair. During the conversation, he stressed the importance of "knowing how people sit in a chair." Learning about how people sit.... it is much more complex than one can imagine. It requires so much knowledge about people, material, art, culture, or lifestyle to create a simple "comfortable chair" for users. The height of chair and armrest, softness of seating, durability of material, coating of surface, and etc... When we start listing up all the possible considerations to design a "comfortable" chair, it may take countless number of pages to fill. It becomes even more complex when designing "a comfortable chair for general public," because nobody has the same body shape, preferences, and lifestyle.

"Understanding how we sit in a chair is the basic and most important skill to design a comfortable chair for people. The comfortable chairs can also be beautiful"

Through the conversation with my friend, I have learned that industrial designers aim to create products with the approach of "people first." How about designing long term care facilities? How much do we know about the life of elders, staff members, and visitors? Are we putting people first or design first?