I guess the reasons depend on the environment, in my case a multi-platform embedded product. E.g. in my case I don't have a use for dynamic node instantiation. Testing partly requires fiddling with hardware and diverse system architectures, so these parts have to be done manually. Delivery bundling isn't fully automatable as well, so there isn't a place for Jenkins in the go-to delivery pipeline I have in mind. It would just complicate things imho. So what's left is SCM-based triggering of builds, unittests, dynamic tests (valgrind, sanitizers) and system tests.