@boag
Standard shounen/seinen(/shoujo?) isekai throws the main MC into a fantasy world typically with game-like stats and are overpowered or laughably underpowered... possibly becoming overpowered later on. All things that are as believable as you can imagine and that's about it. A lot of time is used in describing the (mostly similar) setting which slows down their pace. While there is character development, it takes a backseat to the daily life of main characters and fighting.
For all the ones I did follow, they all became absurd at some point; the authors all eventually stack on so much powercreep they become near impossible to follow. Their beginnings are all vastly sad/boring tales too.
Otome game isekai throws out all the stats and starts with a similar premise, especially ones focusing on a villain female (which most do). The setting needs very little description to be understood by the audience. So they can get straight to the absurdity of taking a random average female and placing her in a snobby/cruel/arrogant female body. As the setting typically needs little description afterward, most of the focus can be on the hijinks that ensue for the characters.
Regular isekai typically have to explain how magic, skills, strength, item creation, gods, races, fighting, etc work. Otome game ones don't need to for the most part. If they do, it can be described quickly to get the point across.
That's my opinion of why they are more instantly captivating than your average isekai fantasy/vrmmo adventure.