You're being extremely reductive about the nature of "having a clue what it's talking about." The lack of precision in casual English (and, probably, human language in general) is getting in the way of true understanding.
Yes, there are humans who bullshit and bloviate and say things they don't really mean or understand. But that's worlds away from not even having a distinct consciousness that can "understand" anything.
To the best of my knowledge, none of our current AIs have anything that we could meaningfully call consciousness or understanding. The vast majority of them have a set of static "trained parameters" that dictate how they are likely to respond to various stimuli. These parameters are going to be tuned for particular kinds of stimuli. They have no continuous state, no continuous input, and no continuous learning. Every time you submit something to GPT-3, it is just taking that discrete input, sticking it into its neural network, and blindly spitting out what comes out the other end.
I don't know the details of how LaMDA is set up, but I'd guess that it's very similar: it gets discrete inputs and produces outputs that look very much like what a human would say based on them, but it has no internal experience of them. It's not "making decisions", it doesn't have a mood or thoughts or emotions of its own, because that's not how our current generation of AIs work at a fundamental level.
In terms of consciousness and sentience, these AIs aren't just not on the same level as a human: they're not even on the same level as an animal. Even the most basic animal, one that's got no theory of mind or sense of self or anything, is still operating in a continuous feedback loop of input, processing, output, and most animals have enough of what we understand as a mind to be able to continuously learn, and have an internal life of some sort. Watch your dog or cat, and you will be able to see that they have emotions and thoughts, even if they are not thoughts on the same level as our own (most of the time).
AIs have none of this. The entire idea of a current-gen AI "having a clue what it's talking about" is just meaningless, because they have nothing with which to understand it.