Your bitcoin will be lost, think the last number i heard was that some 10-20% already is lost. Eventually, given enough time, all bitcoin will be lost.

If you buy stocks or gold, or even just deposit the money you get if you sell your bitcoin, in a bank, at least those funds will be in your name and will benefit your children, and/or someone you care for.

Even if you do share your wallet and your private key with a loved one, they might lose it or forget where they hid it, or it might accidentally be tossed away at the dump or something to that nature.

When there is no official link between your name and your funds, the likelihood of it getting lost is very high if something should happen to you. You dont even have to die for that to happen, it would be enough for you to get brain damage or in some other way be unable to get access to the wallet.