Air Canada fundamentals compared to what?

I've been holding AC for years on and off. It has a P/E of 3.89. Silly low.

Alaska Air has a P/E of 22.

Delta P/E of 9.

Amercian Airlines P/E of 41

I understand that AC is Canadian and is also 6% owned by the fed gov but how do I compare this companies numbers with other companies to see what is a fair value. To me, a pe that low seems like a great value. It's numbers are as good as when it was trading at 50$ per share in 2019.

It was trading at the same price right now as it was when it had neg EPS in 2021. I never can figure out.