Your point #4, while not invalid, is of minor importance. I’m still kicking, and expect to be for many more years. The kids shouldn’t (and don’t) base their retirement on getting whatever is left of the Mountain Millions. Similarly, by the time both my parents were in the grave, I had already built up significant personal net worth ... inheritance is nice to have, but I wasn’t depending on it as essential.
Other families (ranch/farm, for example) may have different arrangements.
And I would agree with you. No way is it essential, for me however it’s just trying to adjust the arc of my financial life in an effort to build generational wealth. Akin to hoping to win the lottery someday, children should never build their own portfolios around someday, possibly, maybe, obtaining an inheritance. Thus, the critical step (#3) of helping your children build their very own wealth.