Honestly the best thing we can do is to teach our kids and hope that all the things we got to accomplish for them won't be put into waste. Build your portfolio now. Invest in assets that will be profitable in the long term so you can leave this to your kids.
The truth is, you never really get to know that detail after you are dead will you?
I don’t really see anything wrong with building generational wealth so long as you aren’t doing it at the expense of others and your own personal enjoyment. Of course you’ve got to put in a good number of your years and strength but, be sure to enjoy well enough that wealth because like you said in the OP, you can’t tell what your next of kin will do with all that wealth.
Now, some rich forks just build a foundation and redistribute some of that wealth right back into the community.