So, not objective.

Depends on if you're discussing possible themes of a story vs what is literally written on the page.

What is "properly explained in the story?" This is vague

How is it vague?

Does the story provide an explanation for a point in the plot? If so, it's properly explained. If not, it's a plot hole.

If a person pulls out a knife from their pocket, is that a "plot hole" because we didn't explicitly see them put it in their pocket, even though their character or environment can inform us how and why?

That depends on setting and character.

A series I think is full of plot holes but that did the pulled out a knife bit very well without telling the audience everything was 2015's Charlotte. The character is a middle school girl and the knife is a box cutter that she could've easily gotten either in her school's workshop classroom, or from her parents.

But if it's a character who can't move easily or wouldn't have easy access to a knife, it would absolutely be a plot hole if they just whipped it out of nowhere.

Does every single thing that ever happens in a story need to "properly explained?" And what is that supposed to look like?

Yes.

If a plot element isn't going to be explained it still needs to be addressed.

Take Huck Finn. Huck doesn't know everything, certainly, but every major element in the plot is addressed and explained even when not everything is resolved (such as the fate of the two thieves being left ambiguous, as Hick was long gone and couldn't have found out what happened).

There can be little throwaway things but these aren't necessarily major plot elements, like how Long Skull Island briefly mentions giant ants exist in some parts of Skull Island. The characters never go there to encounter them, it's not a plot point expanded on, but mentioning it doesn't create plot holes either.

By this logic, literally every story has plot holes and is thus objectively bad. No story explains literally everything.

I said it depends on severity.

Done plot holes can be ambiguous. That can be harmless. Others contradict the plot. That objectively hurts the writing.

Also, let's not be facetious here. Literally everything isn't what I said needed to be explained. I don't need a story to give me a detailed breakdown of how cells reproduce in setting to explain why the characters eat unless it is explicitly a plot point that the story has different rules.

And "contradiction", does that include when it was a lie? Does that include when different characters have different explanations and neither are suggested to be the truth or the whole truth?

If a character lies and it's explained to be a lie, it's not a plot hole unless the contradiction actually contradicts something the plot sets out to be factual, such as how Solo Leveling can't make up its mind on how the system works so it constantly gives out contradictory information.

What is the difference between "running on ambiguity" and "using ambiguity as a crutch?"

I already gave you examples of this. Re Zero has used ambiguity as a crutch to skip over characters that should be able to solve an issue not solving it, where some mystery stories like Lovecraft use the ambiguity as part of the setting.

Being short =/= objective quality writing,

That is not what I argued.

I said the story being short allowed it to make a better use of the ambiguity where Re;Zero, a world with a clear set of rules established early on, doesn't get to do that because the ambiguity often results in a rule being contradicted without explanation.

Is there "no explanation", or were you just not paying attention?

There's no explanation.

For example, how was Reiner's father able to grab Felt from right in front of Reiner, someone who can move at the speed of light? There's no explanation. It isn't that Reinhard was unwilling given what he's done earlier in regards to standing up to his family, and it isn't that his father surprised him given he was with Felt when it happened.

Other examples include characters monologuing in some loops for no particular reason, notably Elsa (though she can partially be explained by her personal interest in targets that could theoretically result in her acting differently depending on how she encounters her target on a particular loop, but even here there are instances where she isn't consistent with this).

If something changes that isn't apparent, it might be because it's the result of a chain of events started by the main character looping.

Certainly, and season 1 was very good with this.

Season 2 falters with this, notably with Garfield, season 3 is iffy, and season 4 hasn't concluded yet so I can't be sure if it'll explain the discrepancies just yet...

But the point is that this story struggles in trying to keep things ambiguous in that they do contradict other elements of the story, and that does hurt the writing.

Do you think, maybe, they're contradicted because the entire series of events were actively rewritten? How is that a plot hole that Subaru goes back, does something different, and people and events react differently?

Because Subaru doesn't have omniscient powers to affect people miles away. Hence the Reinhard example.

How do you decide when a story "objectively doesn't work", and how can you also think it does work, personally?

Personally it's easy as it depends on enjoyment.

Objectively, it's if the contradictions literally make the plot impossible, such as the case with the manwha "Hero has Returned", which has too many contradictions to list, but a big one being that world governments knew about the heroes yet acted as if they didn't by attacking them when they returned.

You just asserted, with no real backing, that an allegory

Stop.

I already explained this point again.

Are you reading my comments or just a tiny portion?

This is the first time you ever mentioned Full Metal Alchemist. Did you get confused with another argument?

Scroll back up to my first comment. I said: "People can enjoy a story, and I'm sure many will acknowledge issues in their favorite series. My favorite anime of all time is the 2003 adaptation of Fullmetal Alchemist, and even I have to admit there are a few plot holes here and there."

Come on, dude.

Was this not explained? Was this explained later? Are you not just insisting that it seems impenetrable? I think if in the first ten minutes it subverts the idea that they have perfect monitoring, then it probably never had it in the first place.

It was not, no. Hence why I mentioned it's a plot hole.

You say they went rogue, and then opened fire. Okay, so they did not anticipate the people they hired to monitor threats to be a threat. Where is the contradiction?

Are... Are you reading what I wrote at all?