That was great feedback!
My hope was MMORPG adventure meets special interest in pet collection, and I realized that there was a very Nintendogs situation in that, so I was sort of happy to lean into it (if there was a remastered Nintendogs, I would absolutely play it).
Obviously, there's very little options to completely remove grinding in MMO's without time gating, which becomes really annoying for a lot of players. My thought is that this is a game that can be enjoyed without grinding, but you're right in saying that there are people who would be creating these sorts of breeding "ranches" and economically I would prefer not to get on EVE Online's level so my hope would be that the other intersecting options of how to spend currency in game would mitigate the need for even more complex systems.
As I said, one of my greatest's weaknesses was not considering how to offset competitive edge created by these "Fabled" pets. I do recognize, however, that performance in each competition does introduce an amount of randomness, but creating max values for pet stats is currently a weak point, which needs further development, testing, and balancing to work as intended.
Lastly, the reason the narrative got cut from my document is that I didn't have time to write out story that I felt good about. I'm sure it would be the most fun part of the doc for me, however, I felt that I needed to put a lot of time in considering systems that I was less certain about. 100% not having a great story would keep this game out of development. If I were to continue this GDD and fully flesh it out, my goals would be creating a world and story that supported the gameplay experience I want to provide (a social, cozy MMORPG with a special focus in pet collecting) as well as refining these systems as we've discussed. The main reason I chose MMO over the suggestions you've made is that I personally would want a strong interpersonal interaction component in this game, and I also really liked the idea of trying to figure out how I could change something specific about MMO's to make it new, and this was my fun weekend excursion to do so. I haven't played Stardew Valley co-op, but having played Pokémon Violet co-op, I think having such a lower focus on story isn't really what I'm going for...it just came down to time.