You raise a significant point about the potential for the abuse of power, a concern that has been proven valid time and again throughout history. Indeed, idealistic notions of collaborative decision-making can be naive if they don't account for the ways in which power dynamics, often skewed, operate in the real world.

The question of who gets to make decisions about the ethical and societal implications of new technologies is fraught precisely because of this. Any system of governance is susceptible to being co-opted by those with the most power, and that power is not always wielded responsibly or ethically—as the example of Stalin, among others, shows.

So, while the multi-stakeholder approach may seem like a balanced solution, it's important to remain critically aware of how easily such systems can be manipulated or bypassed entirely by those with the resources and intent to do so.

The challenge, then, is not just to decide which institutions should have a say in these matters, but also to construct mechanisms that can genuinely counteract the concentration of power and provide some level of protection against its abuse. This is a complicated task with no easy answers, but its difficulty doesn't make it any less crucial.