Usually that’s just about denying strategic assets, though: blowing up railroads, collapsing mine shafts, that sort of thing. Blowing up the museums and opera houses is pointless, because the enemy can’t get any war benefit by capturing them. All it does is waste your own explosives, which you’d rather use to blow up the enemy. Scorched earth practiced by attackers, on the other hand, tends to be more indiscriminate: contrast the state of Novgorod post-WW2 with that of the towns west of it, or the treatment of rice fields by North Vietnamese vs. Americans during the Vietnam war.
Usually that’s just about denying strategic assets, though: blowing up railroads, collapsing mine shafts, that sort of thing. Blowing up the museums and opera houses is pointless, because the enemy can’t get any war benefit by capturing them. All it does is waste your own explosives, which you’d rather use to blow up the enemy. Scorched earth practiced by attackers, on the other hand, tends to be more indiscriminate: contrast the state of Novgorod post-WW2 with that of the towns west of it, or the treatment of rice fields by North Vietnamese vs. Americans during the Vietnam war.