Delta and United were each able to raise over $2B in credit. They have plenty of airplanes and facilities to use as collateral. Coming out of 2019 United had about $29B equity (assets - liabilities).

They don't really need a bailout to stay in business. The grant money for employees is contingent upon them keeping open flight routes that they'd otherwise close. Sec. of Transportation wants low traffic (small) cities to have access to medical supplies and whatnot (at least that's what she says, of course she's pro-business as well).