Never heard of this. My 70yo FIL made one. It’s “our life book” lol. He is a retired old school banker so a little “OCD” about spreadsheets and documents and printing everything out. It’s in a 3-ring binder with several tabs, But there’s a backup on his computer in a hidden folder. And the directions to the folder is behind their wedding picture on the wall. Lol
He took my DH and all of his kids through it. It was pretty remarkable. He updates it every month (he’s retired) with new printouts of the items that change.
I have anxiety and every time we take a trip with just the two of us I wonder “what if something happens”. DH and I had already talked about what if something happens to him and he gave me passwords and contacts but this would be so much more useful. So I encouraged him to create one as well… ours will be digital with links to all the accounts - with maybe 1 physical copy that won’t be regularly updated.
He’s “working on it” - in his spare time. I told him He should just pay his dad to do it and it would be done.