Give them an in-game condition that causes them to go catatonic periodically, and now the other players have to deal with the dead weight player character until the player shows up.
Why would you make your other friends suffer because of one asshole? That one guy showed up late? Sorry, we’ve already started, and the party left you as you didn’t show signs of life. Roll a new character in the meantime.
Give their character a disease where they take damage every 10 minutes the player is absent without notice
Give them an in-game condition that causes them to go catatonic periodically, and now the other players have to deal with the dead weight player character until the player shows up.
Why would you make your other friends suffer because of one asshole? That one guy showed up late? Sorry, we’ve already started, and the party left you as you didn’t show signs of life. Roll a new character in the meantime.