@anoman there is one, I forgot the name though.
A grandpa got isekai'd by mistake instead of his 7 year old grandson who he protected from a home invasion.
I think there are several isekai where the MC reincarnating was old when they die, but its usually irrelevant because isekai has a habit of forgetting that the MC had a past life.
The concept is interesting but the execution is such a letdown. I’d love to read the perspective of a homeless guy. This story drops almost all of that immediately to become the usual, trite boy adventure stuff.