while this is an attempt to disrupt monopolies of Whatsapp and such, I'm quite wary of it. if I'll use another messaging service to message someone on Whatsapp, Meta will most likely still collect all the metadata about our conversation, and I bet that's going to stop Signal, my IM of choice, from implementing it.

and besides, it's going to make it more difficult to make people move away from Whatsapp, since "you can already use [the IM you use] to message me".
I'd rather wish it would force the big players to open up their APIs, so people could create alternative clients. I'd love a less bloated and better designed app to contact people on Whatsapp, with all the community and status update bullshit ripped out.

Are you referring to the Digital Markets Act that would force some large tech players to allow interoperability?

I think it's a great step forward, although I think it's only in 2024 that those changes will actually happen.

What?

We'll have to see how it develops, but so far I'm absolutely in favor. I hope this opens up some of the walled gardens and enables real competition.

Nice to have, but ultimately unenforceable and irritating when half baked.

You’d end up with either a basic standard everyone supports and then extends in their own proprietary ways, limiting interoperability to SMS like content (at which point just use SMS, they’re included in every phone plan), or with multiple apps built on top of the same protocol (which IMHO would be better).

That said, don’t we already have the protocol in the form of XMPP? I remember people trying to make XMPP compatibility a big selling point for Skype almost a decade ago, and cross-chat compatibility between Skype, WL Messenger and one of the infinite Google chat services. No idea how that ended up.

Perhaps something like E2EE XMPP, if that is a thing?