Have fantasy sports massively impacted traditional gambling?
Whether it affects or not is not an issue because this is still a gambling term, meaning that gambling sites can include this type of betting on their sites.
Another question people ask is whether what would fantasy sports be considered as... gambling or gaming?
If you bet on the betting market then it is gambling.
It is the same as any other sport, if you just watch or play in the sport then it is not gambling, it becomes gambling when you bet on one of the bookmakers in the sport.