"Most well-" vs. "Best-"

Lately it seems I’m encountering surprising numbers of examples of “most well-”. Today’s include:
most well-preserved
most well-known
most well-informed
most well-loved

ISTM that all these would be improved by replacing “most well” with “best”.
best-preserved
best-known
best-informed
best-loved

Am I right? Is there some sort of style dictum that discourages “best-”?

This is a total stretch, but professional nitpickers could argue that the most well-known whatever could be between two whatevers, but “best” has to be between three whatevers.

Nope. Between two whatever, the more well-loved one is, well, the more well-loved one, not the most well-loved one. If “best” is not acceptable in a set of just two items, neither is “most”.

“Most well-known” seems like a distinction between an entity and other entities, while “best-known” seems like a distinction between specific reasons within an entity.

Gawd, i didnt realize how little sense i made here. Let me explain using examples.

“Nirvana is the most well-known rock band associated with the grunge genre”

Vs.

“Kurt Cobain is best known for being the frontman of the 90s group who killed himself”.

Donald Trump is well-known as a real estate developer
Donald Trump is best known as POTUS 45

(or vice versa)

You can be well known for several characters, you are best known for only one.

But the OP is asking about “most-well known vs best known” not just “well known”.

It depends on what is the “most” referring to, on what the complete meaning of the sentence is. That is: does the “most” refer to “the highest number”, or is it an augmentative of “well”?

“Well-preserved foods can last more than three months”.

Saying “most well-preserved foods can last more than three months” indicates that “a majority of well-preserved foods can last more than three months”; conversely, “best-preserved foods can last more than three months” does not indicate whether there are a lot of preserved foods that can last long or not, only that the best-preserved ones can.

I should have made it clear that I was referring to the use of “most well-xxxxx” as an adjective.

So “the most well-preserved foods seem to be lasting more than three months” would qualify. But “most well-preserved foods can last more than three months” would not.

I think where it falls apart is when the food in question isn’t best- or even better-preserved. Is it then good-preserved? That just doesn’t sound right to me.

I’d say that the difference is that “most well-preserved” first defines a category of things, well-preserved things, and then slices off a portion of that category as being under discussion. It establishes that there are other objects around that are also considered well-preserved, and thus noble and worthy of adulation.

“Best-preserved”, on the other hand, almost has a negative connotation - this one thing is great (or at least as great as it gets), but everything else probably sucks for all we know.

I was thinking along those lines too.

“Well-known,” “well-preserved,” etc. are relatively common adjectives. So if you’re thinking in terms of who’s well-known or well-preserved, it might seem more natural, or spring to mind first, to quantify them with “most.”

But these are different constructions, independent of the ‘best’ vs ‘most well’ distinction. Don’t these sentences:
“Nirvana is the best-known rock band associated with the grunge genre”
“Kurt Cobain is most well known for being the frontman of the 90s group who killed himself”.
have the same meanings as your two examples?

Somehow in my mind “most” in this sort of context is an intensifier, slightly short of a superlative.

The problem with best- is that it’s slightly ambiguous in spoken English

“Donald Trump is the best-known liar in the world” - out of all the liars, he’s the one people know best
“Donald Trump is the best known liar in the world” - out of all people we know to be liars, he’s the best at it.

A subtle distinction, but not insignificant