Groups 1 and 2 are small groups made of friends and we handle everything over text. We do tend to have a lot of “hey, are we playing today?” texts on the day of.
Group 3 started as a work game and has a larger group with less consistency of who shows up week to week. We use discord. Creating events, hosting lore, and places to stash special/homebrew rules is nice.
Group 4 is a west marches-ish game with about 10 players. Discord for that also, though once a group is set for a couple sessions we switch from the discord channel to a group message for communication.
I’ve used Teams in the past as well but I find discord to be better for managing the various things I need to organize a game.