With that argument we should not restrict firearms because there will always be a way to get access to them (black market for example)
Even if it’s not a perfect solution, it help steer the problem in the right direction and that should already be enough.
Furthermore, these researches are also a way to better understand LLM inner working and behaviors. Even if it wouldn’t yield results like being able to block bad behaviors, that’s cool and interesting by itself imo.