Hi :) Sia / Filecoin / Storj and similar projects are solving the problem of storing data/files for blockchain applications. That is more of a general protocol / service layer for other teams who will build blockchain applications.

Zebi is in the similar market, but from what we were able to gather they are focusing on the institutional market and aiming to solve the problems around the exchange of data.

Aside from that, there is also differentiation by geographical market. Zebi was able to secure a contract with a government of the Indian state and working on more of these. Their known competitors are not targeting Indian market as far as we know, even if they will end up providing similar solutions.