The Zenin clan even had another superior CT which is projection sorcery. And the demons with heavenly restrictions (Toji and Maki) who wouldn't have an issue dealing with Blood Manipulation. Other elite Zenin had some good CTs but they could be handled by Choso however (not Noritoshi the student though unless he somehow levels up to Choso's level in the future).

Blood Manipulation is pretty cool don't get me wrong. Actually one of the most fun battles in the manga included Choso and also Noritoshi vs Megumi was pretty fun in the anime. Choso is one of my fave characters (actually top 5) and I also really like Noritoshi (in my top 15 if not top 10 perhaps). However, Blood Manipulation's potential seems quite limited (especially with humans). Choso is probably the greatest blood manipulation user ever because he is a part curse and part human which means he doesn't run out of blood. Human Kamo clan members were always at risk of losing blood in theory (unless they had something else to deal with this major drawback of their CT). So far, we don't really know what made them a major clan. Gojo clan hasn't been explored much as well but at least we know what made them very important and threatening.

That said, maybe Choso hasn't revealed the peak limit of blood manipulation yet. Or maybe Gege doesn't care much about the Kamo clan to involve them in the plot lol. It seems like that so far. Not really exploring the Kamo clan yet is a bit disappointing I must say but it's clear why is that. The spotlight on Gojo clan and Zenin clan must have been due to the main cast having Gojo, Megumi and Maki. Much more relevant characters than Kamo (the student) and Choso.

Still, it would be great to give some spotlight to Kamo Notorishi (the student) and introduce more back story on his clan. Or maybe even let him get trained by Choso.

Also, now that Todo lost his technique and served his purpose in the story to a great degree, it would be great to have another representative of the Kyoto school that takes Todo's role in doing major help to the main cast. That person should be Noritoshi Kamo IMO. He is their 2nd strongest student, very smart and interesting and maybe eventually becomes their strongest student with more growth. Noritoshi and Megumi have great potential to work well together (just like Todo and Yuji).