My first internship when I was 19 and still in college (well, failing out at that point but that's another story...) was at a small consulting company where every desk had a 286 clone running MS-DOS 3.3.
We spent our entire days in SuperCalc 3 and dBase III, and some of the fancier staff actually got to use 1-2-3. I think we used both because 1-2-3 had copy protection and SuperCalc didn't? But 1-2-3 was clearly better.
I had to train the older staff members on how to use a mouse. One person thought you had to reboot the computer if the mouse cursor wouldn't go far enough in one direction without reaching the end of your physical desk area -- they didn't know you could Lift The Mouse Off The Desk to move the physical mouse to a better location without moving the cursor. It is truly hard to explain just how newfangled all this technology was back then in a small office.
A big breakthrough for us was switching from dBase to "Clipper" which was basically dBase on the backend but with the ability to write text-mode UI code, so you could build nice purpose-built data-centric applications for clients.
There was a LOT of data entry, digitizing the stops and routes of city transit maps into dBase and these DOS spreadsheets. The keyboard shortcuts were SO FAST and when we eventually moved to Windows 3 in 1991, I always enabled the 1-2-3 keyboard shortcuts in Excel. I still remember some of them.
I imagine there's nothing unique about my experience: these types of tasks were surely replicated all over the business world, with interns and staff getting their first taste of spreadsheets and programming languages in these powerful, tiny DOS programs.
I'll skip our brief foray into the dead end that was OS/2 2.0 :-)