Are you saying every airline should have held cash reserves (really more likely to be bonds or other investments) sufficient to sustain them through a total wip

Are you saying every airline should have held cash reserves (really more likely to be bonds or other investments) sufficient to sustain them through a total wipeout of their entire customer base for months on end? A scenario that has never happened before in the history of commercial aviation? Resources tied up in cash buffers are resources not deployed elsewhere, after all.