Presumably this 100% tax would also apply to gifts cause otherwise it wouldn't really work but where does it stop? Parents can't pay for college? Buy their children a car? Go on vacation with them? Spend any money on them at all so that they would "stand on their own two feet"? Be banned from giving any financial support to their children when they reach 18?
I mean... it's an obviously not a good idea.
Also the most optimal strategy would be to spend all the money you have in addition to getting a reverse mortgages on any property so that by the time you die your net worth would be as close to 0 as possible. Or just selling everything and buying an annuity.