Every Freelance playlist splits the player population up, fragmenting people into more and more playlists which makes it difficult for the game to fill lobbies with people on good connections when the playlist's population isn't at peak levels. This is a real problem for a P2P PvP game and the same issue is why Bungie put effort into reducing the number of playlists open at any one time for Beyond Light.

I'm not arguing against the benefits for having a Freelance playlist (though I do think playing against a team as a handicap is overblown), but there are very real practical issues Bungie has to worry about related to too much player fragmentation causing negative impacts to the game experience for everyone, those that choose to partake in the freelance playlists and those who don't.

I suspect their hands will be less tied on this when the game better supports crossplatform play which Bungie has told us they hope to support in 2021 (note: they haven't promised it, just mentioned they want to do it next year). At that point the population dips inside the playlists during quiet periods of content should be much less pronounced because the matchmaking will be drawing from a much larger pool -- YMMV on PC if, as assumed, they allow console players to opt out of PC crossplay and most people end up choosing to do that.