I agree that most lenders won't repossess or foreclose if the money keeps coming in, but it can and does cause some occasional complications if you do not reaffirm. Once example I know of is someone who filled out paperwork to reaffirm a car, but someone it never got to the lender.
10 years later, they wanted to trade in the car on a new car, but could not find their title, so they applied for a replacement one. Even though the lender had released the original title to them years ago, the lender balked at signing a release for the replacement title, because their computer showed that the debt was discharged in bankruptcy and never reaffirmed. It was a mess that took 4 or 5 months to straighten out. It was all stupid bureaucratic red tape, but it was still an unnecessary complication.

