(Lack of) Team privacy. Most online collaborating teams give access to their valuable internal data (ideas, insights, solutions, strategies, plans, discussions) to external companies. This generates risks, even for teams which "have nothing to hide".
Easy to use "fusion" of online collaboration tools using end-to-end encryption and zero-knowledge servers by design.
Startups and corporate R&D, legal, executive teams wanting to take care of their most valuable assets.