Where I can work we can choose to submit either electronically, or by paper.
After a work trip, in addition to needing to claim for travel I might also have to claim for hotel and restaurant bills. At least some of these will inevitably be paper receipts. To claim electronically, I need to walk to the other end of the building to scan the paper receipts, and enter my email address on a fiddly MFP machine. I then need to find a desktop (there isn't one at my desk), login and jump through hoops enabling Excel Macros to submit the claim. Often it throws some VBA exception and fails. I then need to pester my boss to login and approve my expenses.
Contrast that to submitting by paper - simply staple all the receipts to a form, write the total value and date, sign it and then lean over to the next desk to get the boss to sign it. It is significantly quicker. I suspect my company isn't unique in this case either in having a cumbersome electronic method to submit expense claims.