sects such as the Jehovah's Witnesses are considered cults and do not enjoy the same institutional benefits of other religious organizations.

That's part of the republican pact. Closed organisations which are judged to abuse their members are not allowed (anti-sect law). i.e. people are not allowed to abandon their freedom and delegate their relations with society to a hierarchical organisation.

The definition of who's in the list of cults is controversial, of course, as it should be.

This is about freedom of conscience, and it is surely more important than mere "religious freedom".

_{It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II}