You said "There is zero chance that an AI can understand the physical world without access to it," which is wrong. It is possible. Using videos is an active research area, e.g. https://proceedings.neurips.cc/paper/2021/hash/07845cd9aefa6... or https://arxiv.org/abs/2205.01314

Thank you for the links, it's fascinating!

Fact is, without a feedback loop that can run physical experiments like infants do from the moment they're born, I highly doubt they will develop a useful intuition using just video. Hence the conjecture