Not all games (outside serious) take lunch plus the umpires do not have to remove the bails to signal lunch.
Sorry, have to disagree with you there....Lunch should be signalled with a call of "Time" from the bowlers end Umpire, then the bails should be removed at both ends....as they should be at all intervals, interuptions and at the end of the match.
Law 16 (Start of play; cessation of play)
2. Call of Time
The bowler’s end umpire shall call Time when the ball is dead on the cessation of play before
any interval or interruption and at the conclusion of the match.
3. Removal of bails
After the call of Time,
the bails shall be removed from both wickets.