https://www.marketwatch.com/story/united-airlines-details-it...
Grants for employee salaries and benefits like health insurance, low interest loan to be paid back, and a stake in the company in the form of equity. And all with strings attached so they can't hand out bonuses or lobby congress.
Businesses operate on revenue and margin and companies like airlines can't justify using even 1% of its revenue to "save" for rainy days. Their tickets have to be as cheap as possible and they have to market to as many people as possible. Its unreasonable to ask them to lay out millions on the chance an act of god rolls through.
As a company they have plenty of ways to raise capital to weather major events, including selling stock, which is what they are doing - to the government in exchange for favorable loans and a grant.