I'm probably just being a goof, but I've honestly never gotten used to playing in a free-for-all game mode in all the years I've been playing FPS games, I just feel they cause too much anxiety in me. At least a little tension and fear of in-game death must exist on an FPS, but for me it gets really unpleasant when I'm playing alone and it's every man for himself. I know that in team deathmatch modes the only real differences (usually) are that there are fewer enemies and the pace is slower, but it makes quite a bit of difference. What's odd is that I've felt this is true even when I'm playing with particularly toxic teammates on CS GO. It's like having an asshole yelling at me is better than having no one at all.
Same goes with battle royale games, I hate being alone while I cross a field or go looting and I don't know who may be taking aim at me.