Young people have always had the power to support themselves without anybody's help. That's how life has worked for billions of years now.

It is only very recently that the industrialized world became completely financialized, so that the cost of life has become artificially increased for the youth. Young people have always moved away from their families for marriage, or for becoming sailors, soldiers, miners, hunters, lumber jacks, etc. It was only the oldest son who would inherit anything, so the rest of them wanted to scram as soon as they hit puberty.

Inheritance-baiting your children is the oldest scam in the book, but people weren't complete fools in the past, and wouldn't stick around if the old folks went too far. A lot of head-butting between generations and in-family as you mention.