People use Excel when they should really use a database, they use it because they want to format something on a 2-d grid, edit tabular data, make plots, do calculations, make projections, etc.
The problems go down to the data structures in use.
For instance there is nothing 2-dimensional about financial reports (and projections), really financial reports are hyperdimensional. Proper handling of dates and times is absolutely critical. Also the use of floating point with a binary exponent is a huge distraction in any kind of math tools aimed at ordinary people. (Mainframes got that right in the 1960s!)
Google Sheets is just a stripped down version of Excel and other than the ability for multiple people to work on it simultaneously, is really no better.
