@simon The fact that Russia uses it is, like the use of Polonium, because Russia wants to send multiple messages. It can reach out and kill or cripple dissenters, it can do so in a way that makes it obvious who was the instigator, it has the ability to deny involvement in a way that makes other states / international law impotent.
Actual death is incidental to the aim of projecting fear.
Novichok isn’t being used optimally. It’s meant to be an aerosol. It’s being used as a contact poison.