The problem here is that people are not trained on YOUR implementation.

Everything you have listed here is very nice to have (offline mode, interoperability, …) , but MS (with O365) or G (with G Suite) are often available for free to students, teachers, and professors at critical stages in life.

Just look at Apple with their productivity suite (Pages, Numbers, Keynote). The market penetration is probably worse than LibreOffice.

The academic setting often carries over to the professional setting. Changing workflows is one of the pain points I would see in migrating to this.

I do think it looks nice and I do hope you succeed though! Good luck.