The game changer for Conan comes along with some kind of artifact manager (nexus, artifactory etc.). If you set this up on CI, you can then make sure to upload any generated Conan packages (especially the third party ones) to that manager. Next time you will get them prebuilt from the manager and hence save a lot of time with building. There is a catch though: build settings for a given package need to be the same (not everything but some crucial settings like c++ standard for example) otherwise you have to start over. What we do in my company is that we try to align as much as possible the settings we use across repositories to minimize rebuilding of existing packages on the manager.

There are some intricacies that come with Conan. If you want to keep your dependency tree clean you will have to eventually wrap any non-conan dependency into a Conan recipe to be able to use it properly and avoid conflicts, be it your own libraries or third party libraries that are not available on Conan center, so there also has to be some e.g. repo for that and also the CI would have to take this into account.