What are you even talking about here?
I am ridiculing the way the powerups in this story works, as if the moment the MC finds a new power, a villain of matching power has to spawn into existence to become a fitting challenge, ad nauseam, to the point that the power-scaling no longer makes any sense.
That's just storytelling, man. If you're interested in reading how a begginer ran into a brick wall and died, more power to you, otherwise it's kind of necessary to somewhat scale the world to him or you'd get one of those mangas where the MC unwittingly kills something way beyond him, powers up to insane levels and then it's just a gag manga. In any case, the "power levels" here are portrayed in a way that while a higher level opponent is incredibly dangerous, the lower levels are still very much a threat to him if they know how to fight. Very much not like DBZ.
Yes, and no.
Yes, it's preferable that a story like this, will have enough wiggle-room for the MC to grow, and have bigger ponds for him to swim at.
No, it makes no sense that the world grows around the MC, like some sort of level-balancing where if you're level 100, a regular sheep becomes level 100 as well. That's not good storytelling.
In a proper story, the MC would have landed in a relatively weak area (god's service), but the narrative would still point out that there's a whole realm above the MC, that he can strive towards.
In the outlaw city, level 15 was lauded as this massive ceiling, that if you can cross it, you'd make it in life, since the massive majority cannot.
The moment the MC crossed that ceiling, we keep finding out regular guards are level 25, some random fisherman is level 25.
Soon, the next city the MC will visit, will have level 30 children because the MC is level 30.
TLDR: This story comes across to me as if the author just came up with the world-building and power-balancing as he wrote it, and did not think a smidgen of an arc ahead. As such, we ended up with: "beyond level 15 is fucking holy shit --> actually no level 25 is baby crap and is completely common, what's the big deal..?".
This is shounen power-scaling 101, and it's not a good thing.
As already established, he is not seen as "high value" beyond what he has or knows about, which the organisation would rather extract from him than bargain for. Is this a particularily smart way to operate? No, but it does have parallels with how commoners were treated in feudal times. If you, dared to demand better treatment from those seeing themselves as your betters, you'd see the same development.
1. The very fact that the narrative has so little screen-time with the Guild is odd, almost as if to ignore talking about this issue.
2. It was not "established", not in my eyes. The first contact with the guild was in an outlaw city, which didn't expect any proper members. This is not the same case.
3. Considering we saw how 2 guilds personally trying to recruit the MC, it's beyond a shadow of a doubt that it's weird for the adventurers' guild to ignore the MC, if not at least from the perspective of: "If you're not with us, you're against us". And preventing him from him "against us", means protecting him. Like it or not, narratively, the MC became a major player in the city FAST, and the way the Guild ignores him, to me, comes across as contrived. The parallels of feudal times are moot, imo, because, again: Adventurers' Guild. Their members are commoners. The power-structure of the world is orbitting around levels as much pedigree. If the Guild would ignore promising members like Yajin left and right, they'd have no members.
I wouldn't be having this issue, if it was established ahead of time, that this particular adventurers' guild is run by an incompetent fool, and the adventurers suffer for it, but it remains afloat because of the guild master's strong background and backing -- or if the guild had an ace-party, that felt threatened by the MC, so they sabotage his ability to get support from the guild. I'd even argue that'd be much more interesting of a development, rather than just.....Ignore the guild completely, and just assume it's normal for all other factions to ogle the MC, rather than the guild he's already registered with.
I already wrote a fuckton, sorry this is getting so long-winded. I get that this story, obviously, takes strong inspiration from medieval societies, and it plays them off very well most of the time -- but what I mentioned, how the MC is always the underdog, just so easily comes across as a narrative choice, rather than a reflection of the setting. This is the point I am trying to dog so hard here.