They're adjustable (so aerons can be at least ok for ~everyone), and durable, and pieces can be replaced. It's like commercial kitchens vs. home chef -- more e

They're adjustable (so aerons can be at least ok for ~everyone), and durable, and pieces can be replaced. It's like commercial kitchens vs. home chef -- more expensive, but flexible, and meeting a lot of standards/requirements which make sense in commercial settings but not in one-off settings. There's probably a $100-200 chair of some design which works better for each individual than the $1000 aeron; it's just a different $100-200 chair for each person. And it probably will not last 7 years in daily hard use.