> Lock-in through the network effect is lock in.

Exactly. If your complaint is about being locked in but the platform you use is the one everyone has to use because of network effect or otherwise you yourself are locked in with that platform.

The network effect only results in lock-in if there's an obstacle to using multiple networks at the same time. Obviously no-one is going to carry around two phones, so that's how Apple achieves lock-in. By contrast, keeping two or more messaging apps running is trivial.

And SMS is irrelevant.

SMS is just terrible though, and is just not worth using. It is plain text, limited in size and simply has less features.

What anyone means when they say SMS post ~2010 is SMS/MMS

It didn't get better.

That's just like, your opinion, man. SMS/MMS is decentralized, open, and works on every modern mobile phone out of the box. No other text messaging technology does this yet.

Open for Verizon to read/modify, you have no way of knowing the other half’s identity (was their number given to someone else in the meanwhile), no encoding is specified/due to non-ASCII characters taking more SPACE (in 2022) so auto-SMSs still today will just force ascii text, making it often unreadable. Like, it is literally a single digit number of bytes difference.

Also, you need like.. a carrier plan to access, wouldn’t really call that open. Any network based messenger can work over my home or even McDonald’s wifi, without any third-parties

I get what you’re saying but your home or McDonalds wifi is decidedly a third party, although encryption may mitigate that.