CalyxOS implements many random 3rd party stuff as if that was their own.
Apart from 2 (QKSMS and Bromite) being unmaintained, installing random apps as system apps (if this is what they do) means a system update may cause data loss for users, when removing those apps. And it has the problem of a way too high goal that can not be reached. They simply dont maintain those apps, so dont ship them.