Not paid per hour, paid per trip. A trip consists of an aircraft blocking out of a gate and blocking back in at the destination gate.
Compare a productive day of flying continuous back-to-back trips, that pays 7.8 trips vs. a day of numerous aircraft changes, ground time, reschedules, airport waiting and an unscheduled overnight that pays 5.6 trips.
Return to normal pay rates in 2021 has been stated for non-contract employees.