Not sure if I’m doing something wrong or missing something but at the moment the only way for me to add a new row or column is to use the + button at the end of the rows/columns. Adding this new row/column appends it to the end and is not movable. It also means scrolling all the way to the end of the sheet to add this.
Most of the time my use case is to add a column to the left or right of an existing one or to add a row above or beneath an existing row.
Would be great to have this functionality, I use it all the time in G Sheets.