Your Bitcoin portfolio is an investment, so getting old or even death should not be an avenue for you to liquidate your investment. Just like companies and big bank balances are inherited by children of it's owners and others contained in your will, you can decide as a father to split your holdings and issue them to your children as part of their inheritance in order to keep holding even after you've left the earth. Having given them proper orientation on the importance of holding for longer, they can keep holding and increasing the value of the portfolio handed over to them. That way you're still holding for a longer time even in death.
Is it correct to call a company and Bitcoin the same type of asset? Is it OK to bequeath Bitcoin to someone? Such questions are natural.
Because investing doesn't require much knowledge to start, but you must acquire knowledge to manage investments. As you have gained knowledge and been able to retain and grow your portfolio, is your successor a worthy candidate for that portfolio? Employees of your company to perform duties to qualify your successor for the company, or you train your successor to qualify for the company. How long your successor will hold on to Bitcoin is questionable. Bitcoins are very easy to sell compared to companies. So if you fail to raise your child to be worthy of holding bitcoins, is it okay to leave a bitcoin portfolio to them? I think every investor should have a qualified successor, just in case. Before his death, he should take the responsibility of making the successor competent by imparting education. If it fails to do so then it is better to opt for an alternative method.