re: is a power of attorney for aging parents a good idea?

Yes.

You, or the most trustworthy sibling, should take control of everything in some way. When one of my granddads died all things were taken control of by a trust for Grandma. Even her house. She never has more than $2500 (discretionary spending) in her bank acct during the month. Things like vacations are all arranged and money monitored, which she does a few times a year, as traveling around the world is her thing. All bills paid for separately. I don't think she can legally get married without approval, if she wanted too. Essentially every and all ability for her to get dupped by anyone from family to a stranger was nipped in the bud, as apparently she owns nothing to give or sell away. At least that's the way we (grandkids) were told to avoid us from hitting her up for to much, but don't know the actual specifics.

Medical POA was good to have "just in case" during covid too.