Sexiled: My Sexist Party Leader Kicked Me Out, So I Teamed Up with a Mythical Sorceress!
https://mangadex.org/title/4aee683e-ad5f-4fdb-a803-b873a806a28c/onna-dakara-to-party-wo-tsuihou-sareta-no-de-densetsu-no-majo-to-saikyou-tag-wo-kumimashita
Sexiled: My Sexist Party Leader Kicked Me Out, So I Teamed Up with a Mythical Sorceress!
https://mangadex.org/title/4aee683e-ad5f-4fdb-a803-b873a806a28c/onna-dakara-to-party-wo-tsuihou-sareta-no-de-densetsu-no-majo-to-saikyou-tag-wo-kumimashita
It kind of reminds me how English novel/serial titles used to be, where it'd be a short title and then a second title that's like a one sentence summary of the story. It almost makes me wonder if that's not just a more intuitive way of titling things and the preference for paring them down as much as possible and disdaining long and descriptive names is just a cultural aesthetic trend.
Or maybe it's just a good way of advertising "this is slop, it is a treat for you, and we are not pretending it's anything else or trying to be cool and mysterious with the name, you're getting exactly what it says on the cover" for pulpy stuff like light novels and manga.
I think it's just a matter of telling the consumer that this is the slop they want as quickly as possible. That's why the stories and settings themselves have been in a race to the bottom to be instant-gratification power fantasies (sexual or martial), probably most obviously with the gamification of settings with literal in-universe menus describing everything in terms of stats in a way that would make Akira Toriyama blush. Actual story beyond power fantasies is withering away, a process hastened by constant pruning.
I do think long titles can be fun. The first example I always think of is: The Pilgrim's Progress From This World to That Which Is to Come: Delivered under the Similitude of a Dream Wherein is Discovered, The Manner of His Setting Out, His Dangerous Journey; and Safe Arrival at the Desired Countrey. It's quite a lot like what you describe, since it doesn't just give the premise but explicitly summarizes the plot.
It also strikes me as a tonal shift from the title styles in the 90’s and aughts where it would be something like “Elementia Axion” named after whatever MacGuffin was in the story. We went from “Sounds cool, gives you no information about what it will be like” to “Awkward title, lots of information about the title.”
Thinking about it, I wonder if it's an adaptation to trying to compete in an oversaturated market, like if the idea is "there is so much to pick from nobody is gonna look at the summary of a work if the title doesn't really grab them, so the title should be the summary instead" so that it's more visible to the people who want exactly what it bills itself as.
Probably also reflects the shift to a more web-dependent industry/market, where verbose titles are more useful for gaming SEO.
I think this is the primary answer to why there's so many "oops I fell unconscious and woke up in an exploitable fantasy world where being a creepy metagamer means I have a slave harem" creep pandering slop titles.
Right, work in whatever flavor of sexual feature is focused on in the isekai in the title so it turns up when horndogs search for that term.
"Oh no I fell unconscious and now dare ye enter my magical realm?"
That's exactly how I see the names of the ongoing sewage pipe outflow of isekai waifu "exploit this world that is not yet ruined by capitalism and enslave everyone in it with capitalism" trash.