How does blue-chip sustain its profit-making abilities during this COVID-19 period?

A blue chip is a stock of a company with a national reputation for quality, reliability, and the ability to operate profitably in good and bad times.

For instance, Dairy Farm International Holdings. This name might sound unfamiliar to some but it's the parent company of Giant, Cold Storage, Guardian, 7-Eleven and more. This company is resilient in both good and bad times since people need to eat regardless of economic situation.

Another example can be Singtel. Telecomunication is critical to an economy. People will still need to communicate either through calls or SMS (OTP) or the internet. It is an essential service that will continue persist in the economy.
But not all blue chip stocks can be very stable. Take a look at Singapore Airlines. Due to the nature of this economic downturn, travel is severly restricted or completely banned, badly affecting the national carrier's business. However, it can be argued that the airline industry itself is very volatile. The business' profitability is highly dependent on crude oil's price and economic situation would you still travel overseas for holiday knowing you might be retrenched soon?