I think the challenge there was fit with a boundary receiver who's a plus blocker. None of that is really his game, and depth wise they had Shakir and Samuel. They've since added Moore as another similar type of player to McConkey.
Is McConkey as effective a player when outdoors, or when its cold ? It's a small sample size, but the splits suggest - no, he is not - https://www.pro-football-reference.com/players/M/McCoLa00/splits/2024/. And that was with this slate of outdoor games: New England, Cleveland, Denver, Pittsburgh, and Carolina. So 3 of the worst teams in the league, and 2 playoff teams where he had 7 catches on 14 targets for 77 yards and 0 TDs.
It's hard to say one way or another with a really small sample, but i do think sub 9" hands can be an issue with a cold wet ball.