Lionel is, but it's mostly junk now.
When did it start being "junk?"
American Flyer was part of the A.C. Gilbert Company.
The brand was bought later by Lionel. My Christmas present from my parents in about 1958 was an American Flyer train set. In about 1996, I purchased an American Flyer passenger train set from Arizona Trains. The quality at that time seemed to have pretty good. I don’t know if Lionel still makes American Flyer.