I think if the bitcoin holder dies the coins that they have will probably gone because they are only one who can access it. In addition to that, if they pass it in their son or daughter I think the bitcoin that they will still in their wallet because they can access it.

This question is itself a question in his own way , Because if any person have such a big amount than surely he will not remain hide to his family and also he will no more hide to Thier trusted person , with such a big amount he will surely tell to their memeber that how you're this big amount because to earn bitcoin in bulk amount is not a easy task , so surely he will expose to his family .
Here I myself have a friend in another city ( 1000 km far from my house ) since I have not yet meet face to face but still I know he is trust and I told him that when I got died then please get my private key from my place ( secret in online ) and sell them for money .

Just in the world will remain less bitcoins. Accordingly, Bitcoin may increase slightly in price.

If their relationship members know their private key of wallet. they can own those Bitcoin. If not, those coins exist but no one can use them.

If the bitlocker holder dies without leaving anyone with information about passwords and secret keys to access these bits, they remain encrypted in the blockchein block chain. However, we can not say that they disappear forever. They stay there until someone chooses a digital password and opens access to them. While such a technological opportunity does not exist. However, quantum computers may soon appear that can pick up digital keys of any complexity, including, to my knowledge, passwords of this level of complexity. That is, in the future there will be an opportunity to gain access to lost bitkoynam. However, this new technology poses a potential threat to the safe existence of crypto currency. How to solve this problem, while it is difficult to say.

Of course no one can touch it. It can't be mined or be owned by someone. Although it can be hacked. Aside from that there is no way it can be used it will be lost forever.

i've read in the past that a dude made a certain script that sort of asks the owner if he's alive like every month. and if he didn't reply after a few months, the keys would automatically be sent to a certain relative. cool stuff.

Absolutely!!

It's prudent to keep a trustworthy person as your secret keeper. Otherwise all your wealth is gone!!

it will disappear all, and your family can not enjoy bitcoin. then I suggest that you inform your bitcoin to the family. so that, when you die, you will inherit the bitcoin.

That would be very unfortunate situation cause with the death of the bitcoin holder there also comes the "death" of the wallet. If the user has not stored his private key anywhere or trusted his wallet belongings to anyone the wallet will be forever lost in the wastes of the internet. If someone has a lot of the Bitcoins the best thing would be to share his private key with someone of importance, maybe not the private key but the storage of the private key. The best thing would be paper storage for the private key.