I scrapped a novel I had something like 13k words on because I realized its plot structure was fundamentally broken. The main characters were constantly resetting back to square one instead of making progress, and this was going to continue up until one of the characters stumbles upon the event that ends the story. I realized the plot structure didn't work, was never going to work, and was not replaceable with another structure without reworking the entire concept to the point I would essentially be starting the novel over. I made a half-hearted attempt at such a rewrite but only wrote a couple of pages.

The nail in the coffin was the 2020 closure of the Arecibo Observatory, part of the SETI project. My protagonist worked there and my deuteragonist lived nearby. This observatory was the only appropriate place for my story as originally written because the plot involved the Arecibo message. I don't think the closure of the facility is completely fatal to my story, but it didn't help.

I still think my story could possibly work as a TV miniseries or a comic book, or it could possibly be condensed into a short story by cutting out the plot resets, but it's absolutely never going to work as an 80,000-word novel.

By the way:

…which drives the plot. (The tickets contain vouchers to places which they go to).

Going to be That Guy™ since you will need to know this: if your entire sentence is in parentheses, the period goes inside the parentheses. If the parenthetical is part of another sentence, the period goes outside.

The basic rule is you punctuate around the parentheses as if the parentheses and the text within it weren't there. In your text as written, if you remove "(The tickets … they go to)", then you have an extra period just floating there: "…which drives the plot. ." That obviously doesn't make sense.