I agree with tatsu again and besides tf2 is an objective based hero shooter as well and fortnite isn't even an fps, it's an tps battle royale which is a completely different genre. But the fact that nobody would be able to tell it is an indie game if you slapped on a 'call of duty online' label on ironsight and released it as such, speaks volumes for the quality of ironsight. There really hasn't been f2p games that have this high production values before.
Also mifire,once again, the demographics for cod and ironsight are very different. Simply because cod costs 60 bucks while ironsight doesn't. So it allows ironsight to be be accessible to the free to play market as well, which cod can't tap into. Meaning even those broke college students can just jump into ironsight and have a good time free of cost.
But as I've mentioned before, there is one other reason one might look to play ironsight over cod that is simply because cod has become really different with specialists and specialist equipment, which is more akin to rainbow six siege + cod has lost the magic of it's old map design, instead now favouring mindless the run 'n gun shooting which is much, much more casual. So yes the other reason someone might look into ironsight over cod is it's fair balance, as there are no specialists so everyone is on an equal playing field from the start and the only difference is preference of loadout which makes for much fairer competitive play as well.
Alas, I rest my case, I shall reply no more. Spectre out.