Quantity of death should have no impact on whether something is terror or not. 10 people died at Astroworld, that was obviously not a terror attack. If the Boston bombings had merely injured people instead of killed them--or even if it had miraculously failed and hurt no one--we would obviously still call that a terror attack. No one is going to be scared to visit the Capitol on January 6, 2022 or 2023, unlike how people were afraid to go to las vegas or the Boston marathon after the attacks.