Long ago, the pioneers of digital shooting pitted two teams against each other in a contest to earn the most frags. Thus, the perfect game mode was born.
When an FPS features team deathmatch at or near the top of its playlists, that's the crucial clue that you're playing a good videogame. The mode's popularity has waned in our current era of battle royale and extraction, so it's nice that some newer shooters (that aren't Call of Duty) are keeping pure multiplayer fragging alive.
