I've never found a good argument for scanning stuff
Just a few...
1. Takes up less space. Once it's in electronic form, you can throw away the paper.
2. Protection. Once scanned, I can back up the electronic documents to multiple drives. If there is a fire, theft, flood, etc. I still have backup copies of my documents in my safe deposit box.
3. Preservation. Many store receipts are printed with thermal printers. Those printouts can fade over time. I recently cleaned out my old paper file cabinet and many of the receipts were completely blank, despite being stored in a dark temperature controlled box. Paper documents can get dirty, torn, etc., but I can always print out a fresh new copy of an electronic document.
4. Easier to Find. With a good folder organization system, I can quickly locate any bank statement, pay stub, or store receipt. Or I can use a simple file search if I can't remember where I saved it. This comes in handy if I want to know something like when I bought our TV.
5. Sharing. It's easy to email or print out scanned documents if you need to show them to someone to qualify for assistance, a discount, or whatever.
Of course, if you can get documents electronically in the first place, you avoid the whole paper, mail costs, scanning, etc.
Contrast this to a scanner: Power up, oops fix the driver, update the computer, scan the document.
I open the door to my ScanSnap, insert paper, push button, name the file.
That's far easier than getting the key to my file cabinet, unlocking it, finding the appropriate folder, inserting paper, put folder back in cabinet, relock cabinet, put key away.
Then spend an hour searching the hard drive for something you "know is in there somewhere". Then you are away (or dead) and someone needs to pull some of your information together. Forget it! Anyone can open a file drawer, but not anyone can get into your machine and find documents.
You can use the same organization system electronically that you use in the physical world. For instance, a folder for electric bills, another folder for water bills, or whatever. No difference, other than the paper version takes space. As long as you organize your files well and name them appropriately, you should be able to find them as fast or faster than with an old file cabinet.
As for other's accessing your files, I do keep a short instruction sheet in a notebook in my desk drawer. If I die my wife or daughter can use the sheet to access any files they need to, though my wife already knows how to get to them. I keep the password to the encrypted financial drive in our safe deposit box (mentioned in the instruction sheet), so a thief can't just open the desk drawer to access our financial records.