Fake news.
I just rerolled and what you do at leveling isn’t what you do at end game.
Leveling i was just doing whisper caches meaning just a ton of open world events like hell tides, Legion events, aspirations.
Once i got max level i started doing NMDs, Infernal hordes, lair bosses and the pit.
3 of these activities you literally can’t do until end game.