They don’t know you’re immortal. Just another member of the team, someone Fury added temporarily because your abilities made you tactically flexible and Wanda was recovering from an injury. You’re able to cover as just about anything on a mission. Close quarters, long distance, stealth, tank, shield. Hell on occasion when no one was available you do solos. You were quiet and kept to yourself, not on purpose. The team already had their dynamic. It was supposed to be temporary… that’s what you told yourself.