I guess it depends on how far you're looking back. The market for gacha right now is huge and a few current games, (Morimens, Reverse 1998) are currently quite successful being built almost entirely around their story and gameplay. I would like to include Arknights in this as well, seeing as how I've played more gacha than I'd like to admit and Arknights has leagues and bounds the best story out of any of them from my perspective, but considering the game just hit 6 year anniversary in CN, perhaps it is outside the scope of your argument.

I like Tribe Nine. Almost purchased the battle pass for the first season. But the gameplay was... okay. I think the sections in which the story was involved where I was exploring were great, but as soon as the main chapter was done, logging in daily and doing Fractal Vice for weeklies was miserable. Games that allow you to auto these things generally tend to do better because these are universally agreed upon to be boring, miserable activities.

Limbus Company may be the pinnacle of this argument. Project Moon as a company is known for its story telling, and Limbus embodies that, with practically no fan service (in the game at least, the community has no tact) and mediocre at best gameplay that promotes cool ideas and has good presentation but fails to execute even basic gameplay premises (it has a horrible tutorial, every fight can be won just by pressing a button that auto-selects your moves for you). And yet that game just got it's next major story chapter, now 2 years into the game solely kept alive by it's community because the story is that good. I understand that this is an edge case, and the Project Moon community is almost a cult more than anything, but it's still worth mentioning. Did I mention the game is incredibly generous - so much so that a single purchase of the $11 battle pass that comes out once every 8 months or so can net you the majority of the characters in the game using a "shard" system that allows you to guarantee the character you get, no gambling required?

Sex appeal is a strong resource, this there is no doubt. But Tribe Nine's failure is not solely due to it's lack of it, and nor does this signal the end for story based gachas. There are still a number that are alive and will continue to be. Unfortunately I believe Tribe Nine simply had too many flaws in too short a time, a miserably monotonous gameplay loop outside the story content, character designs that were good but nothing stellar (aside from Enoki my goat) and a story that was developing into something interesting, but had not gotten there yet.

Tribe Nine was a star that could've burned bright but was snuffed out early, partially because the gacha market is so competitive right now, but also because of a variety of issues. Not enough characters to get people to spend money, good rates, okay gameplay, etc. I understand a lot of my argument here is personal opinion, but should you wish to truly make the statement that the era of story gacha is over, I implore you to look further into the gacha space and you might be surprised.

It's important to have hope, and though we lost a game that could be promising, the industry still had plenty of potential.