I'm not familiar with MDF, I have seen the guys on This Old House use it for interior door/window frames and molding. I worked one time at a place where we made sewing machine tops with particle board. They were really heavy.
Where I live, furniture factories or related businesses used to be about the only places to work. In the seventies when I went to work most of them were already using particle board. One local manufacturere still (last I heard) makes solid wood furniture. I said local, but they were bought out by a large company years back.
Most of the case good furniture is made overseas now. China, Indonesia, Vietnam, etc. All the companies bring it in. One company I used to work for turned one of their plants into a warehouse for imports. The only work now is unloading and reshipping and some repair work. But, supposedly it helps the consumer out by giving us cheap goods to buy. A man that owns a furniture store said a few years back that his wholesale prices hadn't went down any
Anyway, the Chinese particle board I saw on a sewing machine cabinet my wife bought last year isn't like what used to be used years ago. It seemed to have bigger chips and less glue and didn't seem as strong.
I have seen particle board used on some upholstery frames that came from overseas. Anyway, I digressed from the original question, but I am not a fan of particle board, and I could relate some more about Chinese made furniture and empty buildings around here, but maybe in another thread.