There is definitely skill/ knowledge in FF. Skill as in understanding players, matchup, strength/ weaknesses, waivers/ trade strategy. Of course there is luck as well, nobody is arguing against that.
People like to sh!t on FF as all luck where anyone with zero knowledge can win.. look that can happen in any game and even in the NFL, but reality is that those that know what they are doing will consistently finish in the top 3rd of the league. You can set up a league to reduce the chance of lucky wins somewhat. In an 8 team league your draft is your team and even on auto draft you will have a great team. Very little use for waivers as your only decision is which stud to start.
In 10-14 team league with expanded rosters and inj you have to research and even watch games.. as stats alone can be very misleading and there is a LOT of bad advice out there from so called experts. Here true football fans will usually do much better than those that know nothing about football.