Too late now, Rex is here to respond (Note: tl;dr answer is No F Way, it takes me approx 1 hour to get from level 60 to level 65 and more to get to 71 even with this update and usable gear)
The game needs to change the LOWER to mid range levels instead of the higher levels, example: it takes 10 minutes to get from level 1 to level 5 solo (give or take 3-5 minutes based on gear), could you imagine it being harder at lower levels (monster has MORE life, not dmg output) making it longer... now you still need to add in the reward, let us be honest, do you really want to spend 20+ minutes going from level 1-5? Hell No, BUT, if you have the gear, the challenge that you want would still be there.
Let me put it this way, low tier items like;
Arcane focused heal IV,
Heals: 70 to 84,
+72% Enhanced Effect,
+16 Strength,
+2 Dexterity,
+2 Critical Strike,
+7% Heal Mastery,
+1% Wind Mastery
would actually be useful to use, but since you can 1 hit kill basically every monster spawn (for me including EPs) at level 5, it is useless to have 72% ee, dang it could have been 10% and still be useful, the 16 str stat helps kill faster of course etc.
So, use diminishing returns (life) at lower to mid range upwards of monster life until it balances out time-wise.