Why not unlock myth and BC now?

[Gamemako]

And WP, AK etc are already at "useless" stage if you'd like to call it - literally something people just run for quick myths or just for relic quest. Do people farm Primal HM for weapons these days? Nope because you have Primal EX weapons already.

Players are not ilvl90 in a day. You start at a point where you cannot even attempt Titan HM, let alone extremes primals and BC. People do still farm HM primals for weapons, and people still gather philo tomes for Darklight gear. The claimed 2.2 grind is vastly easier than the present grind to i70. If that went through as you envision, the amount of viable endgame content would decrease.