Isn't the Jolla UI and parts of the userland closed-source? If that's the case how can one be use the OS is free from "surveillance"? This also doesn't take in

Isn't the Jolla UI and parts of the userland closed-source? If that's the case how can one be use the OS is free from "surveillance"? This also doesn't take in account the privacy issues about what the baseband firmware contains.