True collateral damage, though, is where you hit a military target, but injure/kill civilians nearby, or you miss your target and accidentally hit civilians. Deliberately aiming at civilian targets, especially hospitals, is a different thing altogether. Admittedly, innocent civilians wind up dead in either case, but there's a big difference in numbers and intent.
I don't disagree with you, but I feel that it's more opaque than the dictionary definition and perhaps the perception of the major population.
What Russia did was a war-crime and as you mention, not collateral damage in the truest sense. But, as part of the wider operation, they'll say it is.
Armed forces have an objective. While they may not intentionally want to kill civilians, collateral damage is the euphemism for acceptable killing to facilitate it.
In layman's terms, people feel the term describes those who are accidentally killed or injured, whereas it's actually used to account for those deemed acceptable.
The Russian army clearly has a much higher threshold that those in the west and it's deplorable, but let's not kid ourselves that our forces have limits too.
By the way, I'm not justifying it in any way - far from it. It may also come across as heartless how it's described and that's not my intention either.
However, in reality, this is how military systems work.
