Modified gravity is still being actively explored and I would argue taken very seriously but not in the context of dark matter, rather in the context of dark energy. So in a sense, yes, modified and dark matter combined are both possible in the same theory. However, at the moment, there is no real reason to suggest both dark matter and modified gravity are responsible for things like galaxy rotation curves because one of these works just as well without the other. In fact, many modified gravity theories apply "screening mechanisms" so they don't impact galaxy scales
Sabine Hossenfelder has a great series of videos about both dark matter and modified gravity theories (https://www.youtube.com/watch?v=FN2d2cmi_Gk, https://www.youtube.com/watch?v=2VNcDoLNJk8, and https://www.youtube.com/watch?v=468cyBZ_cq4). I think she does a very thorough (and relatively easy to understand) job of explaining what both of the types of theories are, the motivations for developing them, and their strengths and weaknesses. The first video is about dark matter, the second is about modified gravity (mostly focusing on MOND), and in the third she talks about how she thinks it makes sense to accept both. Even if you don't agree with her position, her videos are still very informative for anybody who wants to know more.