Risk is part of fantasy football. A big part.
There isn't a player in the NFL who doesn't carry some risk. There's always the risk of injury, which is seemingly greater with some players than others. There are risks involved with roles for some players, and situation for others.
On draft day, those risks have to be measured against the potential reward a player can deliver. And a decision has to be made: pick or pass.
Of course, not all risks (or players) are created equally. Some players carry only a nominal risk into a season: Patrick Mahomes is expensive, but barring an injury, he's going to do Patrick Mahomes things and put up Patrick Mahomes numbers.