It's occasionally a survival strategy, rodents will eat their young if they are exposed to high levels of stress immediately after giving birth. Some sharks do it in vitro with their siblings.
Edit, higher mammels tend to offer up the ability to sustain the young as a valuable survival trait, except male lions, if a male lion takes over a pride the first thing it does is kill all the cubs so the females go into heat sooner. Nature is harsh.
I've already made a couple of comments but I thought I'd throw this one in too, ancient societies held coming of age as a big deal because it meant that you'd reached a point where you were worth investing in, prior to that you were cannon fodder.
This is the reason that the food standard cooking temperature for a variety of different meats in the EU is 80c for a variety of different amounts of time, it's not to kill the pathogens it's to kill the by-products. Edit typo. Edit facts https://www.food.gov.uk/business-guidance/cooking-safely-in-your-business
You didn't have to make it to adulthood, if you made it to five you would likely see fifty on average.
Edit, apologies that it still leaves an average. Second edit, it's also theorised that children don't like the taste of vegetables until they reach puberty, children are predisposed not to eat plant matter as they are incapable of knowing whether or not it will kill them.
There's also the fact that throughout the history of civilization we have to spend more time working to exist as population density increases.
India 70 hour average working week, European cave man 20 hour working week, one mammoth is a lot of food.
China doesn't back losers, they've taken a step back and aren't likely to do anything to jeopardize trade given their current economic issues. A similar trade ban to Russia's would tank their economy instantly.
That is a brilliant summation, well done!