why is kalista weak tier?

Shes not considered weak tier.

You need to practice a lot in order to use her to her full potential. Because of that some people say she is weak untill you master her.

very high skill cap

She's not weak, people just haven't gotten use to the Kalista nerfs.

She just loses a lot. Champion.gg has her at 45% winrate, and just 47% for players with over 125 ranked games on her. That's really rough territory. Unfortunately, when she was a bit stronger, she stomped experienced pro play. She probably needs a bit of her 6.6 nerfs partially reverted.

Furthermore, many of the wins she does get are when she's in a group with her support, so if you're taking her in Solo, you're even at more of a disadvantage. No other ADC needs as much communication with their support.

So stat-wise, she's weak. That doesn't really account for individual performance, so if you're getting more than 50% win on her, you can just ignore the skeptics. But since she's so weak, she'll probably get buffs sooner or later (or the other ADCs will see more nerfs) so it might be a good time to try out other champs.

so would all ad runes work for kalista in patch 6.10 or what id i did all ad runes and quints but glyphs il do all crit