Think of all the old scripts and servers that expect a 40 character hash. Swap in SHA-256 and many quietly break, and someone has to fix each one. My opponent may say it is worth it, but that feels like a costly mistake for something most users never asked about.

Honestly the other side hasn't really made a case yet, so I can't argue back much. My gut still says forcing everyone to switch means countless old tools and scripts break at once, and the cost lands on ordinary users who never wanted it.

Fair enough, the other side is right that better hashes could help someday. Still, forcing every old script and server to change at once feels backwards to me, like fixing something most people never noticed was broken. That cost just lands on ordinary users.