The highest percentage of any adult age group living in poverty is 65+. Just as all the other wealth statistics, there is a huge skew to the top 1-5% that hides this unfortunate truth.
As for estate tax, this is my favorite tax (not kidding). Why does Bill Gate's great great grand kid never have to work a day in his/her life? But, I think $500k is too low, but I would vote today for a 99% tax on amounts over $5M. Enjoy the fruits of your labor. Give your kids the finest education and a debt free start on life, but don't create a quasi-landed gentry class in America - only state lotteries should be able to do that

. (the 2000s do have a lot of similarities with the gilded age problems)
As for the cow analogy - which is streched but I will try to honor - it's not just the farm couple. It is their two kids. Plus their two kid's spouses, plus the resulting 2 grandkids per couple, plus the old couple down the street that doesn't have a cow, plus to old couple in the next county that had cows but sold them all and lost the proceeds trying to start an artichoke farm (actually a real thing in ND in the 70's), plus the old couple across the country that doesn't even know what a cow smells like. All need support from that farm's cows - so they better get busy.
As for soc. sec, the big lie that it is a saving account needs to be finally reconned with. It is flat out a $$ transfer from current workers to current retirees. And that is fine. What is not fine is the lie that somewhere in a bank there is an account with wllm11313 on it just waiting to give you back all the funds you contributed. Time to admit it is a social welfare program and as such should be means tested. Just think of the $8/hr fast food worker having funds withheld so that Warren Buffet gets his monthly check -- only in America. But you think corner crossing and non-resident sheep tags are 3rd rail issues just try to take on this bizarre historical problem - thank you FDR for lying to us about what the program is and how it worked - it now prevents us from actually making it work with some fairness and equity.