first off of the four or five major sports, a football player has the least impact as an individual. secondly you need to hit on mid and late round picks to have a winning team. thirdly there is a shit ton of player movement and you'll never sign any free agents of a decent value and barely any at all if you suck a fat one year after year.

the easiest sport to do it in basketball because the best players are so concentrated in the top 10 picks and of course one guy can turn your whole shit around, in ways that even an elite QB, LT, etc cannot in the NFL. hockey it's not tough either, unless you're fucking edmonton, because you get two or three money guys by sucking and there are other means of getting the rest of the roster (hard cap creates FA and trade movement, plus culturally firings/trades are much more common than other sports). i think it's a hard sell in baseball, unless you're smart AF about it (e.g. Astros) and in the NFL it's goddamn near impossible.