Tixeo was fairly limited in its use and imposed on critical businesses (defence, nuclear, transport, energy, etc.). The aim is to extend the service to more areas, such as SMEs, universities, NGOs, etc., for all sensitive communications.
I don't think the project is intended to replace Zoom and Teams for the general public. Most public ministries use Teams and the Office suite.
French industries have been the target of quite a few cases of espionage by ‘advanced North American actors’. They have therefore been trying to distance themselves from US services for some time now (Google Tchap and Olvide).