There are five categories
1. All characters are versed, with fix roles in each sex scene (which mean I can't choose when to top or bottom). This leads to me not turned on reading one scene and turned on reading another
2. MC is verse, datable characters are strict tops or bottoms. Usually, the characters I want to date doesn't let me top them and I end up focusing on the romantic side
3. SFW (no lewd) or asexual (casual nudity only). I can only imagine how they would be if they ever had sex
4. All characters are versed, with choices in most sex scenes regarding position. This gives more favor to the readers but takes more time for the devs, so it's very rare
5. MC is strict bottom. If you can even find a strict top MC out there, please tell me
Ultimately, it's the devs' choice what to put in their works, and the readers' subjective opinion whether to enjoy it or not