Brent dropped by more than half, below the January 2016 $29 low - from January 2020 over two months. Late March saw 25 then 23 dollars. Shell share price dropped below £10, below the 2016 £12 minimum, but has since gained 50%. Since the low there has been an oil price recovery of 40-50%. Whether cheap oil will help the airlines is debatable, but it should help everyone else as business winds up again.
All things being cyclical, perhaps the 2016-2018 experience is where we are headed. Many opportunities are coming.