2021 was "coincidentally" his best season
Justin Herbert’s pressured dropback percentage by year (per PFF, min 50% snaps):
2020 - 36.6% (7th highest)
2021 - 26.9% (5th lowest)
2022 - 35.5% (7th highest)
2023 - 35.8% (11th highest)
2024 - 33.8% (15th highest)
2025 - 43.6% (highest)
2026 - 45.5% (2nd highest)