I'm so confused. Why is the Fedex guy so invested in this topic?

I'm a second year FO in one of our relatively senior bases (ORD). I credited 100+ hours per month with 17 days off in summer months. It's not impossible to make more than guarantee. Yes, premium pay is fickle and unreliable. But no one here is saying you should plan your budget around premium pay numbers. The point is that those kinds of numbers are possible. Not guaranteed. Possible. And not just wildly outlying numbers like the $700k paycheck for people with exclusive "special gigs." Possible for regular ol' lineholders.