Spreadsheets are successful because they are immediate. You can open a blank grid, put a few values in place, and get useful answers before a formal application project would have finished its first meeting.
That speed is real. The problem is that the same freedom that makes a spreadsheet fast also makes it hard to maintain once the model matters.
Relationships get hidden in cell references. Business rules spread across sheets. Important assumptions live in comments, colors, or memory. A small change can be correct in one tab and quietly stale in another.
EndFun starts from the opposite premise: keep the immediacy, but make relationships visible. Tables, collections, filters, groups, and derived values should be part of the model rather than an accidental pattern in a grid.
The goal is not to replace every spreadsheet. It is to give teams a better place to put spreadsheet-shaped work when the work becomes durable.