At the same time, I've always wondered about the collision of office software with issues around decentralization versus centralization.

For instance, when I've thought about why I resort to the web-based suites, it's usually because of backup and collaboration. But when I think about it, there's no reason that you can't just specify some cloud-based automatic backup in a desktop app, and it's been puzzling to me that LibreOffice or someone similar doesn't try to integrate some kind of decentralized file sharing stuff like syncthing into the editing workflow. It just seems like there should be tractable ways to provide the same backup and collaboration services without having the software all sitting on MS (or Google) servers. Why not transfer the collaboration algorithms to some generic cloud server you specify, or in the context of decentralized storage?

With really large documents and lots of editors, the web suites in my experience can become unworkable. I personally think there's some big opportunities for something like LO or another open-source office suite to really shake things up in terms of decentralization features. Maybe I'm just missing things, but so far I haven't really seen them.

Google Docs is absolutely bloody useless at DOCX reading in every way, and messes up quite simple documents, but nobody ever raises this objection.

LO is really fantastically good at reading the fake standard called DOCX. In my experience, it handles it more consistently than MS Word - which is notoriously incompatible with other versions of itself.

Put it this way: I believe this class of objection when the objector links the LO bug, with a test document.

Sometimes. Online Word chokes on many things, and misses simple stuff like center aligned columns.

Did you have these fonts installed, or LO was forced to use substitutes with slightly different metric?

Just having identical fonts available is 99% of solving the layout problems.