I prefer main characters being alone kinda like the MC in "solo leveling" (even though he has a couple of people he cares about, he doesn't actively seek out others) but hey at least in this manga there is no harem nor ecchi which is great since 90% of isekai have horny boys getting pined over by hornier girls -_-
The only one that fir this category and I'm currently reading aside from solo leveling is "I Am The Sorcerer King Webtoon". He does have a team so to speak but he does nothing for free and is smart and calculating (not in a malicious way but he isn't your typical shonen "let's save everyone because we're the good guys" kinda MC)
Second Life Ranker is quite similar to solo leveling. It's good. Currenty it have 40 chapters.
This is a good story.
It'd be even better without the annoying female sidekicks.
I'd much rather have him be alone, or change the female characters to be less invasive. It makes me uncomfortable watching them overstep boundaries that are pretty impolite, though I know that's the type of people Yuu gets along with most probably.
Nina, for instance, wanted to become Yuu's friend even though she previously did nothing to help Yuu though he was being bullied.
And in 4.2 when she gets beat up because she thought it would cause trouble for Stella and Yuu, that was really pointless. She's powerful enough to escape or fight back and silence them. And Yuu ended up saving her anyways.
RGH I dunno. I just hate the female characters.