[rmbeard]

Google Colaboratory is now Ubiquitous in the sense you use the term, as is Microsoft Azure Notebooks, so the Ubiquity argument is no longer unique to Excel. The big argument in favor of notebooks is transparency and the breadth of tools that they can make use of. Economists will increasingly move away from Excel as the QuantEcon website demonstrates. Perhaps accountants will still uses spreadsheets, after all they invented them, but it's unclear why anyone else really needs them when there are better tools available.