>>bwb+(OP)
Not so much "aiming" as doing it. The alternative already exists, is open-source, and used by 40,000 government users. By 2027 all government agencies will use it exclusively.
>>mcoliv+hh
My bet would be that "the standard" will be Heinlein Groups (company behind mailbox.org) OpenTalk (already better than Jitsy) and now they are doing OpenCloud as scaleable NextCloud alternative. The company behind the projects needs it for their own usecases, has stable business and they have decades of experience.