@WindowsEnthusiast my comment had nothing to do with FFA, it'd be nice if you explain your point more. I think making games continue after first checkmate is an interesting idea for Teams, especially in the scenario you described. It can create cases where a player sacrifices himself to give his teammate a winning endgame, and it emphasizes individual skills, which is something Teams has been criticized for lacking.
You answered your own question. FFA is the variant that is more about individual skill. This is similar to variants of chess where baring the enemy king yields victory unless the other player can bare the first player's king on the very next move. Teams is inherently about teamwork.
@WindowsEnthusiast my comment had nothing to do with FFA, it'd be nice if you explain your point more. I think making games continue after first checkmate is an interesting idea for Teams, especially in the scenario you described. It can create cases where a player sacrifices himself to give his teammate a winning endgame, and it emphasizes individual skills, which is something Teams has been criticized for lacking.