Having been there with several parents and in-laws, the care level indeed starts looking more and more like that of caring for a child, and progresses to a younger state. Stop driving. Remove access to ovens & burners. Remove phones. Remove control of finances/ bills ... Stop mail except for reading materials. Lessen/ simplify/ remove choices. Prevent ability to leave the building unaccompanied.

At some point the care becomes a FULL time 24 hour job, whether provided by family or commercially (expensive!!).

Prepping options are limited to your own lists to make sure they are getting the care they need.

For loved ones with memory problems, the best advice I've heard is to live in their world. Don't try to convince them they are wrong - it really isn't necessary, and confuses and hurts them. For example, I think I know what I'm talking about ... and my wife says that she agrees with me. I'm happy. Life is good.