This is precisely what I'm trying to illustrate. No, Excel does not have the same accessibility as a calculator UI. Excel is somewhere in between a calculator U

This is precisely what I'm trying to illustrate. No, Excel does not have the same accessibility as a calculator UI. Excel is somewhere in between a calculator UI and bc in terms of how discoverable and usable it is. Engineers fall into this trap a lot - projecting our own preferences onto what we think other people should find accessible. Most people require training before they can use Excel. The training required to use a calculator is so minimal, they teach it in elementary school. And a REPL is gibberish to the vast majority of people, even if you dress it up with nice colors and friendly messages (which to be fair help a lot).