To answer your two questions, no and no.

Where are you seeing this prevalence of use? I've only seen people use "liquid water" when they are clarifying that the water's state it is not solid or vapor. You might not believe the clarification is necessary, but others might so the speaker (or author) employs its usage.

What about people using 'e.g.' followed by a list that ends with 'etc.' (e.g, '(e.g., grammarians, nitpickers, etc.)')? [(I had to try that, despite possible criticisms. :-)] Does not the use of 'etc.' indicate the writer's list is intended not as just a limited set of examples but a totality of possibilities, thus obviating the need for the 'e.g.'?

Have you noticed "grave" doesn't have one?

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