Flyer1

I agree with most of the answers already posted about why Excel is so ubiquitous. To respond to this comment specifically, though, I'll just mention that we use a product called EASA to enable us put a web app on top of critical spreadsheets while also connecting to a database i.e. you can "de-couple" the data from the logic. There are some use-cases that describes this here: https://easasoftware.com/case-studies/amlin-reducing-risks-e...

...and here: https://easasoftware.com/case-studies/leaseplan-transforming...

What you describe here is exactly what we are doing with a tool called EASA. It enables us to very quickly create web apps using an existing spreadsheet as the logic module. You don't need to be a dev to do this - our BIs find it straightforward - the closest you get to code is a bit of SQL.

It works well - we have successfully applied this to about 20 really critical spreadsheets for functions such as pricing, deal valuation, risk analysis, and even for engineering analysis. Users simply use a web app (that can look like the underlying spreadsheet - or not). The system is also integrated with SAML, so authentication is there, and you can also integrate the apps you create with 3rd party systems - we are looking at launching Excel-based pricing apps directly from SF.com, for example.

Anyway, the site is https://easasoftware.com/ - there are some vids there which probably do a better job of explaining it than I have done here. It's not just about putting an app on top of a spreadsheet, but really putting an app on top of processes that involve spreadsheets. And you can use things other than Excel as the logic module, like Matlab, R, Python - in fact we are dabbling with using EASA to deploy ML models created in Python.