Lotus Improv for NeXT (1990)

I've been looking at the history of spreadsheet software lately due to personal interest in making a video game where spreadsheets are the primary form of interaction. when I came across this video of the now-forgotten Lotus Improv I was blown away.

why has innovation in spreadsheet software design stagnated so much in the past thirty years? why are the main spreadsheet application offerings today (Excel, Google Sheets, LibreOffice) all still so firmly rooted in the VisiCalc/1-2-3/Excel mold, instead of offering anything new? are spreadsheets just destined to be the same until the end of time?