By the nature of how ADCs operate, kaisa is destined to be perma garbage with her current range
The ADC game is a game of effective ranges, and hers is waaaaaayyyy too low. Yes she has abilities that can transcend her auto range, but they're nothing in comparison to other range extending things like clean cuts from xayah.
Kaisa will permanently be garbage unless riot decides to omegabuff her numbers so she just stomps people in spite of that weakness.