France is leveraging Matrix in Tchap https://element.io/fr/case-studies/tchap (part of La Suite Numérique https://lasuite.numerique.gouv.fr/#products recently featured on HN).
Presumably there is funding or resources because of that.
I've always thought the really low bandwidth support they added a few years ago was to support the french subs. It matched all the requirements of VLF/ELF communications.
France donates to the Matrix Foundation (which helps the protocol retain its neutrality and independence, and is very much appreciated), but doesn't currently financially support Element's dev as their upstream. We're trying to fix that though!