Thanks for translating!
You know, with how the old jerk group being upstaged is standard for this sort of story - I really like how this one let our MC go off and do stuff and build up a good rep before having to face their disaster. It helps us see that his skills and talents were overlooked and neglected rather than the quicker "we were too dumb to recognize god tier mc-overpowered and booted them out cause we are too big to function now"
The thing here is that it was never a question of ability, they knew he was good at what he did that's how he got into the guild in the first place and why they even offered to take him back after he quit.
They just didn't like his take care of your dragons mentality. It's the same as say a ranch having race horses and only one of the care taker actually does his job at taking care of the horses. The others only see them as tools to make money and not living creatures simply because they can't communicate with them.
The really stupid part is, it's not like he's the only one who cares for dragons. So far only that specific guild treats dragons that way, we've seen other owners, dealers, etc treat their dragons well it's just the MC is the only who can satisfy what the dragons really want due to his ability.
But yeah, I like that the MC isn't trying to upstage the guild. He's doing what he set out to do from the get go, make a guild that takes care of the dragons they employ. And him upstaging them is only a byproduct of his kindness.