I personally don't have any issues with LB right now gameplay wise, but they just made adjustments to Sigil Of Silence (Doesn't it not Silence anymore?) and she's still Miss 20 Minutes In I Fall Off A Cliff. I think changes might be coming. Maybe just numbers, though, lower bases and better scaling would probably help her out in the late game.
I agree with you.
Besides I'd add that LeBlanc is a character with really poor teamfight presence, which is a thing most tend to underestimate and should be taken into account when facing her. If you force teamfights and act so as to avoid her to do a pick on sensible targets (aka, the team needs to ward well and avoid having the carry go facebrushing), she becomes unable to tilt the balance in favour of her team.
I had games with her in which I was the most fed on the map but still couldn't do anything because of this. It's part to the counterplay she offers, imho. She's good 1v1, she can make good picks and jukes, but she cannot pressure objectives and performs poorly in teamfights. If the opponent groups up, her menace gets halved.