We have some lack of clarity, I think as to what consists of a "list" question on the site and why they are undesirable, per recent meta Q (Not) closing question for Spells with Concentration vs Spells with Thunder/Lightning Damage. I think it's worth discussing this in a more general manner.
So, let's start with some context.
Context To Read Before Expressing Your Opinion, And Clearly Treat In Your Answer, If You Want To Be Taken Seriously
Meta: SE: List questions: Community Wiki? (TL;DR We don't host them)
RPG.SE: Are list/collection questions on topic? (TL;DR No)
Meta.SE: What is the definition of a list question? (TL;DR Asking a question that will be answered with an unbounded list of things - not necessarily the same definition we used in the previous link, I'll note)
"List" questions are often talked about in the same breath as "shopping" questions, so it might also be helpful to review 'the way to ask that right'.
- Meta.Gaming.SE So what actually is a game rec?
And of course following this network wide guidance, after flirting with trying to do better and allow it here, we've banned shopping/game-rec/tool-rec questions.
Now, this does leave some room for ambiguity. There are unbounded "opinion" lists, where answers will be one or two of a large set of possible answers, often distinguished from each other only by opinion - the classic "shopping" question.
Then there are questions that are best answered with a list of things in a single answer. "Here's the three magic items, two spells, and a whatnot that will make you permanently Large size in D&D 3.5e."
Between these we have some other kinds. There's the "completable list" - like Comprehensive list of WOTC D&D 4.0 products? It's a long list, but won't change any more because 4.0 is over.
Then there's the "can't be complete yet" list - like a list of D&D 5e products, which at this point is "evergreen." On topic, or off topic? It'd certainly require curation over time, but that's not the kind of "list question" Meta.SE bans network wide.
And the "maybe answer with a list, maybe with a resource" questions like Is there a list of wizard spells by level by school? where the best answer is a link to an online spell DB or whatnot.
And then there's the "short list, but no one knows how short when the question's asked really" questions like Sets of spells that have explicit bonuses when used together, or the thunder-and-lightning question and its linked concentration question.
We have discussed some that short lists are OK, possibly if CW-ed - we almost never use CW any more, but even SSD recommended it in this context just a year ago per I want to post some questions that will require (finite, community wiki) list answers. Kosher?
So what kind of questions in this general category are on or off topic and why, and is the answer "don't ask them" or "ask them in a different way?"
Clearly, "individual answers make a list" is off topic.
Very short lists are totally OK; many questions on the site end up being answered with "these four classes fit that criteria" or whatnot, and that's fine.
Then we have two separate axes I see on these questions - how dynamic they are and how trivial they are.
Long ever-changing lists seem like a PITA. I'm not real sure of the value of us trying to keep these up and whether that really is an effective use of our format or not (probably not).
Triviality is in the eye of the beholder, but many of the list Q's that are just "read books and list X for me that meet a criteria" are on that line IMO.
Is there an orthogonal solution? With game-rec/tool-rec's we've said "well - ask about your problem not your assumed answer." So can you ask "how can I find all the spells that require concentration," and an answer that's either a short list (if short) or a link to a resource (if long/dynamic) be a good Q&A?
I leave it to the community to answer and vote. Please try to make answers not "discussiony" - if they don't evolve into a clear actionable answer with the most upvotes, then it tends to be a waste of time. Answer, adapt your answer to take the aforementioned resources and peoples' comments into account.