There will never be a reason to pick Sivir if something isn't done about kleds ult

As it stands, Kled has a potentially longer lasting, much more potent Sivir ult, that also does damage to a target. The only weakness it has is you have to target a location.

The biggest reason to pick Sivir is her potential to start a fight with ult, but now that a champion was given a longer range, much faster ability that does the same thing, you're better off picking an adc that does more damage than Sivir and has less utility.