Are all proverbs considered metaphors or does it depend? Here are a couple of proverbs for which I would like to know if they are metaphors or just statements:
Rome wasn't built in a day.
The best-laid schemes o’ mice an’ men gang aft a-gley.
A bird in hand is worth two in the bush.
Don't count your chickens before they hatch.
If it ain't broke, don't fix it.
Knowledge is power.
Time is money.
You can lead a horse to a water, but you can't make him drink it.
To me it looks as if they are statements about simple truths, but they only take the metaphoric meaning when taken in a different context than the one they literally explain. For example, "No great thing happens overnight" = "Rome wasn't built in a day".
Lexico defines metaphor and proverb respectively as
A figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable.
and
A short, well-known pithy saying, stating a general truth or piece of advice.
So, can we say that all proverbs are metaphors or are metaphors a completely different beast altogether?
EDIT: The question has been closed under the assumption that an ‘idiom’ is synonymous with ‘metaphor’? Is this an accurate valuation?