You are proposing an explanation for why most of these things run on proprietary protocols, an explanation I agree is a component of what's going on, I didn't say anythign to the contrary -- I'm still stuck on trying to demonstrate that proprietary protocols for these things are more popular than open standard ones -- which is being disputed -- before we can even get to talking about what explains this state of affairs!
FTP is the closest file sharing protocol I could think of when I wrote my comment above.
Moxie touched on this topic in his article about web3, where he compared and contrasted protocols Vs platform. He explains why he believes platforms, once they gain a big enough distribution, are inherently at an advantage because they can change and adopt fast.
I can't say for sure what vishnugupta meant, but what I thought when I read their comment are:
* Most people's chat goes over things like Slack or MS Teams -- proprietary protocols. Not the open protocols that do exist like IRC.
* Most people's "instant messaging" goes over things like Signal, Whatsapp, or Facebook Messenger, all proprietary protocols. Even if open protocols like XMPP exist, they are less popular.
* Most people's video conferencing goes over things like Zoom, MS Teams, Apple Facetime -- proprietary protocols.
* I am not familiar with the "file sharing" protocols popular, but I assume the same.
HOWEVER, most people's email goes over open protocols. It's an outlier when it comes to these higher-level interpersonal communications.
(Do you disagree? I'm not sure if you do, or if you're just talking about something else!)
But yes, of course, there are other open protocols that are still very much in use. Including things like TCP/IP and UDP (which almost all of the protocols we are talking about function on top of) and HTTP (which some may as well). Most of these popular infrastructural protocols are also older, where vishnugupta suggested "since then", new protocols that become popular tend to be proprietary. An example of a newer network protocol that was open and standardized and also had a lot of uptake would be good to hear!