I used to be a Lotus Notes specialist, and one interesting thing I noticed is that from the earliest versions it was designed specifically to be a "step up" from a spreadsheet (Lotus of course also made Lotus 1-2-3, which was the original killer-app spreadsheet before Excel took over).

Notes still let you see data as rows and columns and had very spreadsheet-like functions, many of which could be transferred directly from Lotus 1-2-3 - but it was a full client-server system which supported decentralized replication, built-in messaging and email, and a solid security model (yes yes I know it was also a crazy confused mess and a UI nightmare but that's a different topic).

Back in the day, organizations had teams going around finding the most useful ad-hoc spreadsheets and converting them into simple Lotus Notes databases. Other organizations would sometimes also give staff training in building simple Notes databases - not a whole lot more difficult than doing a spreadsheet - and then have expert teams come in and polish them up as needed. This made business software bottom-up rather than top-down, which turned out to be a whole lot more useful in a lot of cases.

In many ways, even after I left the Notes world for PHP and Rails and JS, my career in business software has still mostly been about converting spreadsheets into more "proper" applications.

Spreadsheets are the 'blue-green algae' of the software world: the simple base level that's everywhere and surprisingly essential.