Soraka and Vayne bot lane

where in the hell is the risk playing Soraka? for either the adc or herself. there is no risk at all. not to mention it's disgustingly cheap that she has an instant cast AoE silence. Soraka/Vayne lane might be the most toxic bot lane to try and deal with. because you should take ignite if you want to have any kill pressure at all but you forfeit having exhaust against late game Vayne. lose lose situation and it's bullshit. not to mention Vayne proccing true damage bolts every other auto is fucking cancer as well with the new Rageblade.