I strongly believe that human language is too weak (vague, inconsistent, not expressive enough etc.) to replace interactions with the world as a basis to build strong cognition.
We're easily fooled by the results of LLM/LRM models because we typically use language fluency and knowledge retrieval as a proxy benchmark for intelligence among our peers.
As far as we can tell without messing with complex experiental concepts like qualia and the possibility of philosophical zombies, language mainly helps higher order animals communicate with other animals and (maybe) keep a train of thought, though there are records of people that say that they don't. And now also it allows humans talk to LLMs.
But I digress, I would say this is an open academic debate. Suggesting that there is always language deep down is speculation.