I'm from France too, and Mozilla is already more known than many others in the Open Source space, and their user base is still huge compared to anything else.
Z0mbie42 is young and did not see when Mozilla was the browser alternative before Google Chrome and stole the show. It is coming back today though because users start to realize the "Google problem".
Now Mozilla is a browser alternative and not a services one. But this is a good example of how unrealistic and not so good it is to want to be a "google" alternative. Today Google is everywhere from search engine (the original google) to collaboration, music, pro apps, video, browsers and so on.
Building an alternative as open source is good but it should clearly not be as monolithic as Google is.
Now it's complicated because users want a more integrated experience and open source developers that manage to grow their tool in a specific area dont have that much time and funding to better integrate so it's slow.
Also copying as is Google as Open Source is also not the solution. What about privacy. I believe end to end encryption is key. There are advancement in this area (the project cryptpad.fr we work on is one of them). What about decentralization ? There are tools building up in this area like mastodon or peer tube.
I wish Open Source can come out with an alternative, but it will need to be an integration of solutions, and not only a monolithic solution. Check out Framasoft.org for an incredible list of open source services they host.
The collaborative encryption is exactly what is solved in CryptPad.fr and at the core of the storage model. This is actually key because it's not the only problem you will get once you try to add encryption. You'll realize everything needs to be rebuild with no database on the server side, otherwise you will get only partial encryption. Encryption needs to be built in first and then the rest should be added.
Concerning user experience, do not confuse design and user experience. Yes some design is needed to improve cryptPad, but the user experience starts with making it super easy to start to share something. In the case of bloom you first needed to register which is not needed on cryptpad to start working collaboratively.
Note that cryptPad storage is a bit like S3 but with e2e encryption and collaborative documents built in.. so you could build your UI on top of it, but e2e encryption means everything needs to be done from the client side, not from the server side.
There is also a roadmap. I will contact you. We can meet. We are next to Beaubourg.
