I will be downvoted because most people probably don't play well atm on the PBE + she is cute and like Ahri on live, cute champions receive more defense than anyone else. But remember this :
***When Xayah will be mastered, players will understand that this ultimate remove all of her intended weakness.*
Xayah is actually :
* One of the best wave farmer in the game
* A long Range ADC (you can the extended range the entire fight versus an opponent, don't be hypocrit about this point lol, it will remember guys who argue that Vayne have "bad range", when she just have normal range)
- A powerfull burster
- One one the champions with the best DPS in the game (especially with her belover, for that +40% damage)
- A powerfull duellist
- A powerfull teamfighter
- A good controller for an ADC
But also :
- she don't have escape
- she is not very mobile
And seriously, that's not an hard cost when you are a champion designed like other immobile ADC to be protected to reach your maximum potential.
But that ultimate, who both give :
- extremly high burst (in combination with E, but we assume that no one use it without it)
- a powerfull AoE CC
- the strongest form of defense spell after pure invincibility
It's an error to focus her :
- because you will waste your CD / fail your engage / be controlled and bursted.
But that's an error to not focus her too :
- long range AoE enormous damage ?
Not fair at all. That's something like Fizz E or Fiora W : when they play well, even if you play well too, they will always have more possibilities to counterplay than you. And none of this two have range, the most powerful stat in the game.