You work harder than anyone. You care about this company and that things get done properly. You tie up loose ends, you work late and start early. You carry the team. Lately you feel a bit under appreciated. You're looking for a new role now. But you get some satisfaction knowing the hole you'll leave. They'll suddenly realise how important you were. They'll wish you never left.
No they won't wish you never left. They're going to blame you for all the things the next person can't do. They're going to scapegoat you for everything. They will trash your reputation. Because blaming someone else is always easier and faster than doing work and fixing things.