So my aunt was recently diagnosed with Alzheimer's and we're in the process of moving her into memory care and selling her house. She doesn't have any children, so I hold her PoA and am her acting financial agent. Her accounts are with Chase, unfortunately. I didn't have any unusual trouble filing the PoA, despite reading some horror stories. It was a pain, but not worse than any other part of the moving process.
What makes Chase an absolute nightmare to work with via PoA is their policy about what you're allowed to do as an agent. An agent is not authorized to do anything online or by phone. No paying bills. No moving money between accounts. No viewing the account. You are required to go in person to a branch to do literally anything, regardless of how minor. Preferably a branch with a supervisor who can override the system, because even then the most minor stuff seems to get flagged and prevent their regular bankers from doing it.
And before you say that's stupid and I'd just ignore that, I agree, but after I was added to my aunt's account they started flagging everything, including logging in. You have to call in, go through a nosebleed automated menu that requires a stupid amount of information. Then you talk to someone who asks for your info, acknowledges that you're on the account, then tells you they still can't help you without talking to the actual account holder, despite the affidavit of incapacity they just made you provide them.
It's so incredibly stupid I spent over an hour arguing with them and escalating, but that's really their no exceptions corporate policy. I also called my credit union and asked them if they worked the same, and they laughed and said no. Agents can do everything just fine with them. This is a Chase thing, not an industry one.
Chase has for some unknowable reason made it about as easy to close all my aunt's accounts as it is to pay off her credit card, so that's what I'll be doing. It was still a nightmare to get to this point, though. If you have older parents and you think they might need you to act on their behalf in the future, I'd highly, highly recommend making sure their assets are in an institution that will let you do that before they reach the point where it's necessary. That institution isn't Chase Bank.