One of the better examples still seeing widespread mainstream use is email, and this even applies to multiple stages throughout the email ecosystem: sending mail, receiving mail, managing mailboxes. Imagine if email wasn't cross provider compatible
Email is only useful because each server can send and receive with other servers.
But we all know this, so what the point here?
I would say that my point is that if interoperability becomes more useful than the walled garden approach, then we will see something like this posts call for BYO client. Email is an example. We have interoperable email because it is was more useful than service specific inboxes.
Until interoperability is necessary for Word, we won’t see an opening for other Word “clients”.
Aside: you could argue that Google built Gmail to make a dent in the ubiquity that was Exchange for corporate messaging. It exploited the openness/interoperability of email in order to do this. If you accept that argument, then maybe they should take a page from that playbook and work to make Google Docs as open as possible. Allow for more interaction with external clients. Let a more open ecosystem develop. That might have the potential to diminish the position of Office for document creation.
Or maybe email is just so old, the owners got established before it could be commercialized... it might happen again, but I’m not hopeful. For example, I don’t expect Twitter to care about federating their system with other messaging applications. There is too much to be gained (selling ads) by keeping people on their site.
When one person controls the whole system, it's easy to pivot rapidly. I guess that's another argument against having widely used protocols (even though I disagree with it.)