Well my Dad passed away this past summer and it's been a bit of a nightmare organizing the finances. My mother has been no help at all. I've had to jimmy open strongboxes and go through file cabinets in order to piece together what he had and what bills needed to get paid.
For example, he had an IRA that none of us even knew he had. I realized that he had to take an RMD by the end of this year (or get a 50% excise tax). Because my mother is unable to articulate anything invoving finances, I had to call the IRA, convince them I was my father's son (and not a scammer), fill out forms and get them notarized at a bank along with copies of the death certificate, affadavit of domicile and all that, just to find out the beneficiary (which was my mother). Who will not cooperate at all. She just tells me to leave the money in my father's name and I cannot make her understand the consequences of not taking an RMD distribution.
That is just tip of iceberg of what I am dealing with.
So yes, my advice is to have that conversation with your parents, unpleasant as it might be, before they die, so that things can get sorted out much quicker.
My dad went through a similar event. My mom handled all the money. He was cool with that. She died at 53 and my dad had no clue how to pay bills, where the money was and how much he was worth. I had to have a sit down with him to show him where he was financially. He was about to return food to the grocery store.