Excel gives you the power of being a programmer without having to admit that you're programming. There are people who do absurdly impressive things with it, the CA-GREET model for estimating CO2 outputs is an excel workbook that took me a while to figure out how to even use.
But the barrier to someone using it is much less because it is gentler than, say, giving someone python code to do the estimate and expecting them to do it correctly. I think the interface familiarity is key.
Unfortunately, while LibreOffice is usually pretty good at all this, it's always just one or two peculiar difference in function calls that breaks it. It's pretty close, but just not interoperable for anything advanced.