There is no excuse for a tool to quietly destroy a day's work and call it a feature. The user who posted this story did everything right, opened a CSV, edited it, added new tabs, saved, and closed, only to discover that none of it existed anymore. The file remained a CSV, the new tabs vanished, and the edits evaporated. They understand why it happened. They even checked for temp files. But understanding the technical reason does not make the loss acceptable, and it certainly does not make the tool trustworthy.
What makes this story especially frustrating is the regression. The user remembers a time when Excel forced a clear, full-screen popup before letting you save a CSV. That popup demanded an explicit acknowledgment: you are about to save in a format that will discard data. It was not subtle. It was not a yellow bar at the top of the screen that blends into the interface. It was an interruption designed to protect you from yourself. That behavior existed, and then it disappeared. The current warning, a static yellow banner that users can ignore or miss, is functionally useless. The checkbox under File > Options > Save that supposedly controls it does not restore the old behavior. It just toggles a banner that looks like every other notification ribbon.
This is not a minor inconvenience. It is a fundamental failure of user experience. Spreadsheets are where people store decisions, calculations, and hours of thought. When a tool silently discards that work, it breaks trust. The user in this story is not asking for a radical new feature. They are asking for the protection that once existed and was taken away. That is a reasonable request. It is also a sign that traditional spreadsheets have stopped evolving in the ways that matter most.
The practical lesson here is simple: if your spreadsheet tool can make your work disappear without a fight, you are using the wrong tool. Users should not have to hunt through old forum posts or YouTube timestamps to find a warning that used to exist. They should not have to remember to check file extensions before closing. A modern tool should understand what you are doing and protect your data accordingly. It should warn you clearly, save in the format you actually need, and never leave you guessing. The user in this story lost a day of work. That is one day too many. If your spreadsheet cannot do better, it is time to explore a smarter way to save.