The answer to this is mostly two reasons,

• No consideration of dying soon, and then
  
• No enough asset to start considering a will

Death is something that most persons especially the young do not plan for because it is something that most persons have associated with old age and then for the other reason you start thinking about having a will when you have a substantial asset that you consider transferring to your family or loved ones after your death. A struggling youth has no consideration of a will because they have no property or asset.

The moment you start investing in cryptocurrency and you've accumulated a huge sum in your investments it will be wise for you to start considering a will especially a way to pass this on to the next of kin in the case of your death. It will also be good to also give some education about this to your next of kin in preparation for your death because no proper education would lead to squandering of all the investments that you've spent a good number of years of your life accumulating.