Whiny, "oh no this is awful, I miss being a fast food worker now I'm a god in a fantasy world" Isekai protagonists. If your Isekai situation actually sucks, you can complain. If you're living an objectively better life than what you had on earth, you'd better stop: you're not being relatable anymore, you're being stupid.
Generally, whiny MCs are annoying, but if they have actually nothing to whine about, and it's all in their head, they better have a character act to resolve it.
Generally, whiny MCs are annoying, but if they have actually nothing to whine about, and it's all in their head, they better have a character act to resolve it.