I agree, I was a programmer and had nothing but disdain for excel until for the last 10 years I had to do a lot of data and analytics and so I had to learn excel to things fast.

excel is no longer just a tool and have all sorts of extensions to handle so much data and API integration and web services and complex mathematical derivation.

I do not know R very well as a programming language ( need to know R inside out at architectural level not just as a coder consumer) but I think R or SAS or Python is not superior.

Can R allow a team of 20 people working at different places collaborating code together? I have never been in a situation that R does something that ecxel cannot achieve (probably a little bit longer)

i spent 2 or 3 months taking all excel and data courses from lynda.com later acquired by linkedin which in turn acquired by msft and it was my best investment of time and money. Felt like I should have taken it several years earlier rather than spendinf time with sql oracle and java c++. Unless you are in a real production house excel is just as fine