I hate when articles say "will cost X number of lives". No it won't. It will cut them short, it will costs years off people's lives. Unless it's sterilized people it won't cost lives.
A person may die at 40 instead of 80 but that is still a life.
You could say this about anything though. A serial killer isn't taking lives, merely shortening them. Suicide isn't ending a life it's just shortening one. Literally all death can be seen as merely the shortening of an otherwise longer life, which makes your distinction pointless.
How is the language extreme? For something to "cost lives" means exactly for those lives to be cut short, there is no other meaningful definition. The language used is exactly as extreme as the scenario it describes, by definition.
Do you apply your same logic to other scenarios too? Like would rather that "the tsunami cost the lives of 55 people" be reworded as "the tsunami shortened the lives of 55 people"?
That is not what costing something means. Cost is to lose something which you have, it does not mean to lose the potential to something you don't have. If an apple costs a dollar, it means you had that dollar, and now you don't. The impact of the apple was for the number of dollars you have to decrease by one. If you buy it with 100 dollars it obviously doesn't cost 100 dollars because you get 99 dollars back.
When talking about lives, we don't get them back. People have lives, and if something causes them to lose them, it means costs them a life.
If I own a car, then after ten years of owning and driving it, I trade it to buy something else, that thing still cost me a car. The amount of car I have does not decrease over time but through use. It's quality might, but the count does not care about quality. Same with life. People who are middle-aged do not only have half a life, they are still fully alive.
I think where the difference lies is that you are interpreting "cost X lives" to mean "cost X lifetimes of Human experience" while the interpretation I, and articles use is more like "cost X people their status of being alive"
To make it more complicated does every decade matter the same? Does your twenty's when you are out partying matter as much as your thirty/forties when you are most profitable for your capitalist overloads? What about your nineties when you are frail of health but hopefully surrounded by loved ones?