Are terror zones the only place worth farming for exp/items/keys?

Basically the title.

So, after the addition of terror zones, does playing anywhere else makes sense nowadays, in terms of efficiency?

Assuming same number of /players:

• Is non-tz Andariel/Mephisto worth the time, compared to tz Andariel/Mephisto?
• Are Countess/Summoner/Nihlatak worth to be farmed during tz for more keys, or the drop rate is the same as non-tz?
• Are non-tz Cows worth the time vs tz Cows?
• Is non-tz Chaos/Baal worth the time vs tz Chaos/Baal for experience/leveling?

If non-tz are not worth it compared to their tz counterparts, at which clevel becomes more and more evident that one should only play in tz?

Asking because I feel a bit silly waiting for my favorite/non-elemental-immune/high-density tz to pop up.

Thank you.