@snarlingalt That's just how it is, honestly. Light novels seem to be more about successfully using tropes than creating new ones, but you can be damn sure if anyone does branch out with something even remotely fresh for once, that thing will become common as hell sooner than later. Not that this was ever particularly fresh or new either, it's essentially just time looping like Groundhog Day and what not, but crammed in with all the other isekai and fantasy tropes. It's definitely been used elsewhere in the general scope of manga and light novels too, so stuff like Re:Zero just happened to slide it in amongst the isekai stuff a bit sooner than some others.
I appreciate finding something even remotely unique in these things as much as anyone, but I've pretty much set it aside as a priority. I'm just here to see how these people use the same tools as each other to make things that are still quite a bit better or worse than each other, I'd say. Two of them with almost identical settings and mechanics can still end up not being even remotely equal in over all quality. You could even give both series all the same character archetypes for the cast, and just the finer differences in characterization would pretty much make or break the story when compared to each other.