Interesting, I see the $2.168 billion profit which takes the PAX Revenue of $12,899 (Mainline PAX Rev) + $3,197 (Regional PAX Rev) + $471 (Cargo) + $1,955 (Other Rev) totaling $18,522 in revenue. Minus expenses totaling $16,336 you get the $2.168 billion profit. Regional revenue results in 19% of total operating revenue.

So what you're saying is that the regional operating revenue $3,197 minus the CPA's $1,157 is all profit, but what you fail to acknowledge is that mainline covers all of the other costs of doing business. Without mainline, regional operators would not exist. ACA/Indy died quickly, and XJT tried an LCC with 50 seaters that died quickly as well.