Wasnt it just some dude writing a doc? That's hardly a Google (The Company)'s position.

If anyone other than NVIDIA has a moat, they for sure never talk about it

NVIDIA doesn't have a moat either. Everyone and their uncle is working on or acquiring ASICs for LLMs.

You could say they have a consumer market moat but all it takes is for a Cerebras to release a USB-C plug-and-play appliance.

Generally, a moat is equivalent to anticompetitive power in some way. It's never a good idea to say "we have a moat".