Why are laptops resold as refurbished?

Mostly because companies replace them on a schedule, not because they're broken.

• Lease returns: many businesses lease laptops for three or four years and return the whole batch at the end.
• Refresh policies: IT departments replace laptops on a fixed cycle to keep warranties and support simple.
• Office changes: mergers, closures and moves to new platforms release large batches.
• Customer returns: some units come back from retailers within the return period.

These machines usually have plenty of life left. Refurbishing them gives them a second working life and keeps them out of landfill.