She (?) kind of missed a crucial factor, scale
HA are weapons for small operations, while nuclear and biological weapons are weapons for mass destruction, they exist as deterrents and as ultimatums, their risk is one of their strengths the whole point behind them is to force the opponent to not even dare raise in opposition, or they will be annihilated, in that sense the inability to be able to control the widespread damage is somewhat desired
But even with that in mind, with designer viruses you can immunitize your own population ahead of time, in order to avoid the repercussions of a pandemic
Or putting a conspiracy hat on, capitalize on a pandemic to economically punish and sanction an opponent by charging them for the vaccine, under the excuse of it being a global crisis, hypothetically speaking of course...
On the other hand their direct competition, are information weapons (like propaganda, and computer viruses meant to take down key infrastructure), and automated weapons like drones, which have the major advantage of being able to be designed with a kill switch, if immediate neutralization is needed
In that sense it is kind of odd that her HA don't come with its own version of a kill switch, like poison diluted in blood that requires the administration of a periodical vaccine, or a miniature bomb, instead when mistakes occur they need to use the very tools that the HA are supposed to be replacing (specialized human and animal soldiers), which is a solution that is ironically quite inelegant and prone to failure too, after all the support team hunting the rouge HA are supposed to, in theory be meant to be outclassed by HA