Without getting into all the inside-baseball, these threads are overlooking the most obvious explanation: The Iron Dome system is wired up with a lot of AI capability and if the system detects the missile is heading towards an uninhabited area (and I'm sure they have detailed maps that would track even whether a specific building is currently uninhabited), it deprioritizes interception. When Iran was hitting them hard, the ID system was getting overwhelmed so it would have done everything it could to shoot down the missiles coming for high-value targets, and saved other missiles for last. If the ID system ran out of live ammo for the current salvo, it may be that those unoccupied apartment buildings were allowed to be hit precisely because ID was prioritizing the defense of other, higher-valued targets.
Also, the idea that Iran was demolishing these buildings on behalf of Israel is beyond silly. First of all, a missile is the opposite of a controlled demolition, it does not direct the explosive force inward, it detonates over an entire area. This means that infrastructure like powerlines, water mains, foundation slabs, bedrock supports, and so on, are broken, shattered and ruptured, which is the very kind of thing that controlled-demolitions explicitly avoid. So, no, Iran was not "helping" Israel demolish these buildings, and while ID probably deprioritized these buildings during Iranian saturation attacks, the spin that this was all somehow helping Israel is ludicrous and, if anything, is Israeli damage-control propaganda. Just look at the footage of downtown Tel Aviv, there were
inhabited high-rises getting hit at the foundations with 3,000 pound hypersonic missiles, doing enormous damage to their foundations that, in my non-specialist opinion, will almost certainly result in those buildings having to be condemned and torn down. We're talking multi-million dollar buildings. That's just the civilian side of things. Iran's primary targets were all military targets (including a daylight strike on Unit 8200), and they hit those, too. Secondary targets were energy stations, and they hit some of those. That's not "helping" Israel in any way, shape or form.