Sounds like the typical problem with epic fantasy. Unless you have a pre-determined endpoint and you stick to it, you end up collapsing under the weight of your own sequel baggage. Every new entry is just setup and build up for "the REAL story" that never seems to arrive. And if it does, it's hella disappointing (Attack on Titan). Kentaro Miura once said that after 350 chapters, Berserk was "just getting started." Then he died.
Kiseki is the most successful epic fantasy game series to date, which is impressive. The realities of game development mean long-term plans rarely survive a single sequel (e.g. Mass Effect, Dragon Age). But I think epic fantasy in general is just too flawed to ever properly work.
I made the post you're replying to before I had actually checked out some of the bits present in the game's main menu. Suffice to say, this notion is addressed with full acknowledgment of the fact that they're showing us snippets of stories driven by characters, rather than an overarching tale.
I'm not ultra worried about the future as regards to Falcom themselves, and I'm only just getting started on Daybreak/Kuro. I only needed a little bit to adjust to the new characters and setting, but the game's not missing anything.
I don't think epic fantasy is flawed as a genre. The issue is rather that longterm settings require competent and passionate people who possess the original vision present to work on them. Trails isn't immortal, but it's still awesome; a fact you can tell by just picking up the latest entry and playing through the prologue (yeah, it takes 2-3 hours to finish the prologue, but shut up).
And if you want to get a feeling for just how good it is, look at some of the posters in this thread, ignoring the content of their posts. They just can't stop playing, despite their anonymous, impersonal vitriol (and the fact this forum encourages being angsty in general). I left a comment on
jungl's profile three years ago for whining about Cold Steel, but here he is again and he's already played more than me. He'll be playing these games a decade down the line as well.
They all always come back.
You know why?
Because Trails is king. Flawed as these games may be, there are no better games and probably never will be.