In US, life insurance will not pay outwithout a death certificate. Going missing will never allow one to pay out, until someone convinces a court the person who went missing is dead.
Some policies, primarily Whole Life policies, have a Terminal Illness Rider. These allow up to 70% payout prior to death if someone has less than a year or two to live. Alzheimers is probably not on the list, but each company is different.
Better option is to get a lawyer and put every asset you have in a trust with your beneficiaries as thr trustees. Set up power a of attorney as well.
Yeah, why learn a new skill rather than letting a machine do it for you half as well, while also destroying the environment and tanking the economy?