If you die then your BTC will be secure in your wallet. But if you tell your private keys and password to anyone then he will access you wallet otherwise your BTC will Secured in your wallet for life time.
You are right and that has happened to many people, in fact, for those who have lost their BTC at the time of death, it is because they never left their private keys to family or friends, and this causes a positive effect on the market, because the economy it becomes more and more deflationary, and since the BTC limit is limited, it will never have any inflation, there will always be a way for this economy to survive any eventuality, what needs to be improved is the case that one day we run out of electricity and/or or no internet.