I feel like it has nothing to do with kleptomancy
For me, it has way more to do with the loss of armour and mag res runes, which means his Q does like 100+ points of damage at level 1.
per cast.
per 28 mana cost cast.
he can chunk you for 1/5th of your healthbar for 28 mana. at level 1.
sure he has to aim the skillshot and it can be blocked by minions, but it's so cheap and has such good range (and now has such good damage) that he can very much poke anyone out of lane. And buying a tear doesn't make his Q do less damage (it'll still hurt for 100+), it just mitigates the mana cost even more and gives him more tries at Q harass.
I remember, like 6 months ago I was playing a game (long before the rune change), and I left clicked on my sona support while waiting for blue buff to spawn, and she has no armour/mag res runes. I ask her if she has runes, she says "I do", I assume she has them in scaling stats or in non-stat readable areas like gp/10 or flat health. (Turns out when I checked in match history she literally had no runes equipped). But anyways, we walk into lane and ez fires a Q. it does literally a 1/3 of her healthbar. We of course ended up losing lane super hard because she needs to hide behind me, and can't contribute without risking instant death due to her lack of runes leaving me to 2 v 1 their nami and ez.
And in the current season. That squishy sona vs Ez kinda feels like what everyone has to deal with botlane now.