> In theory, its functions could be replicated in silicon, enhanced for speed, parallel processing, internetworked, and with near-instant access to information. Therefore, AGI could emerge, if not from current AI research, then perhaps from another scientific branch.
This is true, but there are some important caveats. For one, even though this should be possible, it might not be feasible, in various ways. For example, we may not be able to figure it out with human-level intelligence. Or, silicon may be too energy inefficient to be able to do the computations our brains do with reasonable available resources on Earth. Or even, the required density of silicon transistors to replicate human-level intelligence could dissipate too much heat and melt the transistor, so it's not actually possible to replicate human intelligence in silico.
Also, as you say, there is no reason to believe the current approaches to AI are able to lead to AGI. So, there is no reason to ban specifically AI research. Especially when considering that the most important advancements that led to the current AI boom were better GPUs and more information digitized on the internet, neither of which is specifically AI research.