They never had a lot of chemestry as a group. There has been chemistry among members, such as Gura and Ame, but not the whole group - because they where not designed as such. When Myth was selected, Hololive had a different culture. The members where never really gen oriented until gen 4, who had a lot of chemistry and where very close. Prior to that, Cover was looking for talented individuals, and the gen was just a set of individual streamers that debuted at the same time, not an actual group. After gen 4, they started to shift and look for group cohesion too, but Myth fell somewhere in between. They got built as a group in the way that each had a strength to offer to the audience, so there was something for everyone, but not as much in group cohesion and chemistry - rather, Myth was a group of 5 talented individuals capable of shining by themselves, rather than needing the strength of a group. So yeah...
