Man, isekai are such a guilty pleasure for me. This is just me rambling about the "weak MC kicked from party becomes OP" trope, so feel free to skip this comment.
Many mangaka and editors IRL and in mangaka-MC stories have commented that the authors' real life experiences are what inform and enrich their writing. In TTRPG, I found this to be true when my college group had the guys who were the most regular about showing up for RPG sessions, but tended to have the least diverse interactions and the highest rate of rules-lawyering, min-max character design, etc. Conversely several of the players who were more casual or irregular due to other activity commitments tended to come up with more out-of-the-box thinking. Everyone had fun and contributed in their own way, of course -- the regulars knew how game/combat mechanics worked and kept things going. And no one was 100% one or the other extreme.
Same thing with people I've encountered whose exposure to a topic (fantasy fiction, let's say) comes almost exclusively from one source or a very narrow range of related sources. Single-system Dungeons and Dragons-only players, or people who have only ever gone to North American renaissance faires. Or for a totally different genre, martial arts students who have only ever learned, trained, and otherwise known one martial art system, community, training culture, or instructor. I had to initially get through this ceiling myself, when I first got into each activity or topic. New entrants tend to think the entire world of possibilities consists only of the world they have seen thus far. It takes a while to comprehend Shakespeare's line in Hamlet: "There are more things in heaven and earth, than are dreamt of in your philosophy, Horatio."
But eventually, going into new topics with that assumption as a starting point, we can more quickly establish context for the tiny bits of beginner info we first learn. And more quickly progress by asking ourselves what are the things we don't yet know?
After reading a bunch of derivative/copycat isekai, I quickly realized the kinds of writer habits or low-hanging fruit that show up again and again. It was easy to infer the kinds of limited life experiences behind each writer's story or character development. Just like renaissance faire culture has become inbred and grown into its own self-sustaining subculture, D&D art style and character design has similarly fed upon older iterations of itself (as new artists grow up using prior D&D-specific art as references for their own new work). And of course, isekai genre manga.
In a way, it's fun to armchair psychoanalyze the work to guess at the creator's background. The reading experience or life experience they may have had to date.
Specifically and more on topic now, it's really apparent that many mangaka cater to a type of narrative that emphasizes the self-made edgelord character who didn't need anyone's help to become strong. Kind of like immature US people who cling to our secular myth of the self-made man who succeeded in life and business, and often think Ayn Rand is amazing.
OTOH, many other mangaka will use this initial character as a base to then roll in another manga trope for low-hanging character growth arcs or retconned empathy in a touching backstory. MC comes to realize, has a convenient flashback, etc about key memories of a loving parent, tough teacher/coach, etc. And they realize "Oh! I was never alone to begin with!" Obvs this is a heavy-handed acknowledgement of Japanese/Asian collectivism. High school slice-of-life coming-of age stories are often all about this theme, and I think they typically tell it way better than the isekai genre does. But a good isekai can also tell it really well too. I just eat that feel-good candy up when it's done well.
Anyway, I'm biased against these artificial setups that initially cast out the poor misunderstood MC. I get that in part it's meant to appeal to an audience that self-projects their own inadequacies, social rejection, and ultimately often their imperfect or total lack of accepting responsibility for their life situation. It's a big part of growing up, I think.
But at this point, I've spent waaay too many years and hours recruiting and integrating new participants into all kinds of work/recreational teams. TTRPG gaming groups of 5-10 people. Extreme fitness classes and workshops of 10-80 students. Martial arts training sessions. A lot more boring industry jobs and projects.
And often I had to learn to work with the people and resources who were available. When the task itself is important enough and you just don't have enough hours in the day to do it yourself, you WILL have to use suboptimal tools, skills, abilities, and characters/people just to get a few more percentage points of completion on the main goal (IRL to share passion for a martial art, or in-game to clear a quest/mission/dungeon). And that lesson started with my own limited abilities, esp when I had very little experience as a beginner in a particular activity or field. I never had the luxury of a recruiter's market, with a surplus of candidates to hire or recruit. Must be nice to be spoiled for choice of talent, I imagine.
So it bugs the heck out of me to see supposedly successful (dare i say professional?) adventurer teams arbitrarily decide to throw out a suboptimal team member. Delegate lower-risk responsibilities to a guy, closer to within their ability to perform. that's still valuable manpower in a pretty high-turnover line of work. And yes, I realize it's a cheap way for the author to easily set up the arrogant former party for failure, as well as generate a cookie-cutter love-to-hate starter pack of villains.
Obviously, I could take issue with a lot of other weird, inbred isekai/JPRG style tropes, like having teams be constrained to X number of members, explicitly recruiting rigid game-style teams with "the tank", "the DPS guy", "the support mage", etc. But I know that's what the audience is familiar with -- all the more so with a lot of Korean isekai manhwa. At least a strong minority of manga strive to vary up and flip the script on these tropes b/c manga has been flogging the isekai horse for so long that bored writers eventually want to change things up (and look for an untapped niche in a very bloated genre).
Anyway, just gonna drop this into the empty void of the Internet. Happy reading (isekai, that is), everyone!