Edit: that's 17,179,869,184 cells.
Librecalc consumes about 258MB without anything in any cell.
With just one letter in all cells in column A, it consumes 459MB. Per cell, it comes out to 0.196KB.
For all cells, it's about 3216GB. So yeah, not gonna have a machine in my lifetime that can handle a fully populated humble spreadsheet
And yes, Librecalc crashed on my 64GB laptop too.
With just a single digit number, it consumes about 0.08789KB per cell.
That's 1440GB required for all cells.
OK, so that's possible on a high end server.