Pretty much, yes. Fleer brought a lawsuit in the late 70s against Topps, which broke the monopoly and created two new sets (Fleer and Donruss) for 1981. Then in the late 80s-early 90s, all sorts of other brands popped up (Score and Upper Deck, most notably), eventually killing the market. "Only" Topps and Upper Deck remain, although Panini -- known for their stickers back in the day -- are back. Donruss- and Fleer-branded cards are out there again, but they're produced by Panini and UD, respectively.