[Aoi Kurenai]

Sentai and Kamen Rider are both aimed at essentially the same demographic. Kamen Rider definitely presents itself as the more dramatic of the two and can sometimes do things I don't think Sentai would do. Like, they'll both kill off characters that transform, but Kamen Rider can at times do it in a more gruesome manner. That said, I think they both probably have the same ceiling on what they're allowed to do, Rider just maybe goes there more often because you have more mothers in the audience by that point and it helps if the show is a bit more like a J-Drama.

That and when Kamen Rider relaunched itself with Kuuga, being this tonally different show from Sentai helped give it an identity other than "here's another hero show to replace Metal Heroes"