I've had this idea floating in my head for a couple days, where this trainer that lost the finals grows up a bit and starts working retail. They meet all kinds of people, and crazy stuff goes down, and at one point they overhear all of the details of a crazy plan and it's up to them to stop it because the authorities simply wouldn't believe them. Maybe at one point legendary pokemon would try to get their attention? Idk
Should I write this?
Absolutely you should! I’m a big sucker for the ‘average member of society finds themselves in the position to become The Protagonist’ trope, because it puts a level of importance on their choice of actions than any sort of predestined grand design. Basically, I admire people who choose to be heroes than who find themselves as heroes by matter of fate--they are often so much more down-to-earth and easier for me to feel attuned to as a reader.
I’m also outrageously into exploring how civilians in the pokemon universe become impromptu vigilante heroes when there’s so many goshdang crime syndicates and gangs in their world--and since you’re explaining that your protagonist was a competitive battler, it’s all the more interesting to explore how they’d jump back into pokemon battles as a protector instead of as a trainer.
There’s a lot of potential to the idea and I encourage you to explore it to the fullest! :D