I don't think anyone doubted the nature of the technology. The bits were being sent. It's not like we were unsure of the fundamental possibility of transmitting information. The potential was shown very, very early on (Mother of all demos was in 1968). What we were and to some extent still are unsure of is the practical impact on society.
AI and LLMs in particular are not even at the mother of all demos level yet notwithstanding the grandiose claims and demos. There is no consensus on what these models are even doing. There is (IMO) justified skepticism surrounding the claims of reasoning and ability to abstract. We are in my opinion not yet at the "bits are being sent" stage.