Tower gives you a turn of reprieve from birds by killing them, letting them attack every other turn.
With Safe Attacking, the birds are coming at you every single turn, applying 2+ damage (+when you have Aged Sensei or Sparring Partner on the board, or Sensei’s Advice in hand) anywhere on the board.
In practice, Rook isn’t always that hard to kill. He’s harded to kill, for sure, but most colors can skate his maxband two lives decently (Origin Story, Snapback, Free Speech, Nether Drain are all very effective, Crashbarrow and Tiny Basilisk less so but still decent). I rarely have seen Bird’s Nest revive the birds, either because they never die, or an opponent lines up killing them with killing Rook.
BTW if you want to play by forum with or against it, happy to anytime