Airlines are also banks. Their miles are their own private currency. The outstanding miles (liabilities) are often larger than the market cap of the company.
Wow do you have a source? One benefit is miles expire unless they’re United miles
https://m.youtube.com/watch?v=ggUduBmvQ_4
Or as nostr:nprofile1qqs8k0mcqd6sw3h524qn5gslszt9am9knmes3uh268dgnnpv3yfwj6qpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz8nhwden5te0dehhxarj94c82c3wwajkcmr0wfjx2u3wdejhgtcppemhxue69uhkummn9ekx7mp0wy5a35 puts it. The kitchen is worth more than the house.
I’d wager airlines miles are a harder currency than most state fiat. cc @saifedean