aka the pedophile wish fulfillment isekai
Let's just be real here for a moment and acknowledge that almost every isekai based on being "reborn" can fall into the some shade of pedophile category. It obviously depends on how overt the show is about sex and romance. However, the number of shows 30+ year olds reborn and hooking up as children, is high. Very high.
Sekai Saikou no Ansatsusha, Isekai Kizoku ni Tensei suru came out this season and it literally has an old man, reborn as a baby, that has a physical and romantic relationship with a child that is also his cousin. He finally seals the deal when he is like 15 in the new world.
There are a ton of very, very popular anime that follow the same trajectory. I can see how it can put people off and upset them, but I'm not going to bash people that like the shows for what they are. Just like I'm not going to put down people that are disgusted the premise.
It's a weird grey area in anime with tons of technicalities being thrown around on both sides of the debate.