13 points
You just need to zoom in. To make sure it applies to everything, completely close librecalc, open a new spreadsheet, zoom in using the slider on the bottom right, or ctrl+scroll up, until the cells are a good size for you, then close it and that should set the value as the default for all your sheets :)
5 points
I don’t even need this information, but I wanted to say thank you for the great and detailed response!
2 points