Anyone who thinks account wide essences are essential for playing alts are on the wrong track.
"Yey my alt gained rank 3 essences and now I do 2-4k more dps."
But alts are still unplayable because I'm doing like 10k-20k less damage than my main not because of essences but lack of account wide gear. Bis azerite pieces from raids and trinkets play much bigger role than tiny essence upgrades.
Account wide essences were good step but insignificant compared to gear updates from mythic raiding.