PSA: Please, stop rushing BoTRK
it is literally never ideal. BoTRK isn't even a core build item that you run every game on anyone except MAYBE kindred; it is now a counterpick item for high HP. If you rush it on Vayne/kalista, your damage output is going to suck rocks compared to the enemy adc that isn't rushing BoTRK. Please, it doesn't work, stop rushing BoTRK.
-A support main.
Outside those champions? I will agree with you, not worth it