Because it's not always that simple. If the sales for the last 2 years are as follows: 2022 Q1: 0.8m, Q2: 0.7m, Q3: 1.0m, Q4: 1.1m 2023 Q1: 0.9m, Q2: 0.8m, Q3: 1.1m, Q4: 1.2m 2024 Q1: 1.0m You'd be "technically correct" (the best kind of correct!) to say that sales dropped from from 2023 Q4 to 2024 Q1. But in all likelihood, no sales didn't drop.

(edit: dear god the markdown on this site is fucked.)