I envisioned many of the use cases not to store data in the sheet, but to use PySheets as a better Jupyter Notebook: Import data, convert to Dataframes, massage, analyze, learn, and export. A good example is how I have a sheet that loads PySheets usage metrics, converts to dataframes, plots in graphs and then renders as live charts on the pysheets.app landing page.
It's hardly a criticism of pysheets specifically, but I wish spreadsheets were more restrictive (I.e. force sheets into a table format) so that people could build out spreadsheets in an org without creating an unholy mess that needs to be picked apart and reversed engineered in something that isn't a spreadsheet.