We had a lot of. Come pick mom up she drove her car the wrong way down the road and trashed a dozen cars... I read your comments and uh... sounds like fun i suppose XD I hope you have some siblings around or kids that can help out.
I'm probably much younger, but I have a grandmother in her 80s and have to share part of the load managing her. She's not that much trouble, but she clings on to things she can't or shouldn't do anymore. She has problems buying things, and getting devices hacked, giving money to strangers and will throw 2y/o tantrums if she doesn't get what she wants, going to dangerous places thinking the world hasn't changed in 70 years. That said, she doesn't have many people who care about her. It's of her own doing, but at the same time, adults have obligations to adult though.
She has trouble giving up agency, which sounds somewhat similar, but imo, at some point you will have to treat them as children. Either let them learn from their mistakes (lose a bunch of money or something) or start removing their agency. Add yourself to bank accounts, deeds, car titles, etc. Whatever you can to require your sign off incase they do anything dumb, or more likely, naively tricked into doing things.
I had to go as far as to create parental controls on the devices and make the notifications come to me so I could notify a family member or talk to her myself.
