Alex’s E build has the lowest winrate, because it it her by far worst build. I pick Alex very often, but I haven’t touched E build since I tested her for the first time in Try mode in November 2017. Sometimes I go Heat Exhaustion (lvl 4), but it is very, very situational talent.
It is ok in QM, but I strongly advise not to pick it in Draft mode.
Alex is very defensive support. The key how to master her is to play defensively, not taking damage (=dodge as much as you can) and predict your teammates’ movement (to and perfect W). On the other hand she has probably the highest possible healing output across all supports. You can hav easily have 150K healing done even in shorter games. For example Q build gives you 392 (+ 4% per level) healing every 4 seconds and it costs you absolutely nothing, so you can theoretically spam it indefinitely.
If you want to play aggressive support, pick Tyrande, Kharazim or Rehgar. Tyrande can outdamage plenty of assassins if played correctly.
If you want to set up kills, use Pacify (her strongest lvl 13 talent) or push enemies to the wall and block their escape with Wing Buffet.
Why? You can’t kill any frontline hero with E, even if the player is total noob. On the other hand, if you can hit them with E, they can hit you with their abilities. Don’t forget, that Alex is the only support which can’t immediately heal or use any defensive ability on herself!
It works only against bad players. Good team can always retread and fight back when Dragonqueen expires. However, she has such huge hitbox, long range heroes can quickly burst you down anyway. Additionally, you sacrifice very strong talents and you have to wait for lvl 20.
That is true! Meanwhile, you can have second charge and longer Dragonqueen if you go On Ruby Wings + Draconic Discipline.