its wishful thinking or marketing to imagine that LibreOffice is anywhere near this... or Google Docs.
For trivial documents - fine - any processor can do some work. For serious work - MS Office and most likely the desktop version of the app. And after all how did suddenly all desktop apps become obsolete? Well, they are not.
We need a set of stand-alone Office alternatives which are fully cross-platform (so, Electron), backwards compatible with Excel spreadsheets and also offering more advanced no-code functionality, and for the Word/PowerPoint equivalents something with the power of LaTeX but an easy to use WYSIWYG fall-back.
Is that really so much to ask?...
Yes. You cited requirements that to be satisfied together require a huge effort. You want something that can "just work" and is also cross-platform, power user friendly (LaTeX), and should be snappy to be able to gain traction. Not to mention that you have to compete with the ecosystem lockin of Office-Teams-Onedrive-Sharepoint-Azure.
I frankly see no way a competitive alternative could appear without a billion dollar budget backing it.
Which is one reason we don't need Microsoft's Office365 offer at all? I mean, especially in the case of big governments/orgs where they operate an entire fleet of machines, providing good desktop software would be a much better experience than crappy webapps.
Unless of course the goal is real-time collaboration, in which case that's an entirely different use-case and i have no idea how google/microsoft tools fare in this space (but Hedgedoc/Cryptpad are solid).
The real-time collaboration is vastly overrated mostly, and thanks to Google's marketing. How many times have anyone had to do a real-time edit of document. How many times it was crucial for the process. And how is this better than git push/pulls?
Well, there are some 5% of all cases where real-time collaboration on a document is good to have, but 95% of all times is reasonably OK to share a screen and have few people stand right by the side of s.o. performing actions.