What's the meaning of the word glib?

I’ve been studying English for a lot of time and if there’s a word that I’ve always struggled to understand, this word is "glib". I’ve read multiple definitions of this word on various dictionaries, but I still can’t fully get it.

CED has, for instance,

glib: speaking or spoken in a confident way, but without careful thought or honesty:

• No one was convinced by his glib answers/explanations.

Collins Cobuild , on the other hand, gives:

glib: If you describe what someone says as glib, you disapprove of it because it implies that something is simple or easy, or that there
are no problems involved, when this is not the case.

So, the word glib is usually defined as a way of talking that is smooth, ready, fluent, confident, smart, easy … but that at the same time do not show much thought, it’s shallow, trivializing, lacks understanding … To me this is ever so confusing. It seems that these two things don’t go well together. I wouldn’t use it for example to define the way that a salesperson talks, since I wouldn’t say that it lacks understanding and that it doesn’t show much thoughts.

I mean, it seems to be referring to someone that is very well-spoken, has the gift of gab, silver-tongued … so everything that I would associate to being clever, competent, knowledgeable … but instead they are flippant, facile and maybe even dim.

Did I get it? Maybe I’m puzzled because in my native tongue, that’s Italian, I can’t find nothing that is quite the same. I would be very grateful to whoever will provide me with some examples of ways of talking that you guys find to be glib.

Thank you!