I found this article: bbc.com/news/business-47802280; "How computing's first killer app changed everything". While people had been buying computers specifically to run word processing for some time, the article refers to the release of Dan Bricklin's VisiCalc spreadsheet in 1979, for the Apple II.
The claim of the article is that, first, there are now 400,000 fewer "accounting clerks" employed today in the US, versus in 1980. These were the people who, before VisiCalc, made entries into paper accounting ledgers. But there are also 600,000 more full accountants today.
Also, "spread sheet" was a 1970's accounting term for a double page in an accounting ledger.
Begin with "Are we owed money when someone takes our idea?"