SMS by contrast is an open standard.
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.
And SMS is irrelevant.
The lock-in is obvious: if you're part of Apple-oriented chat groups you can't switch to Android without losing access to those groups, degrading the experience for everyone, or convincing each one of those groups to make the switch to a multi-platform alternative. Claiming not to see this is disingenuous.
I'm not sure, but I don't think you can actually uninstall the default SMS from Android phones either without having another app installed at a minimum and then I bet similar to Messages if you were to somehow uninstall that app then the default app would appear since it's probably part of the core operating system (similar to other basic functionality like settings or a phone app to receive calls).
I don't know what you mean by you cannot substitute Messages with another app. If I didn't want to use Messages I would just disable all settings and remove it from the home screen and use whatever I wanted instead just fine.
You are correct that you cannot install Messages on non-Apple hardware. Not all software is open source or available for all platforms. For example I cannot install Playstation software on my Xbox, nor can I buy a Nest Thermostat and install a competitor's software on it (without hacking both of course). There are games that are made that aren't created with support for macOS. Etc.
> if you're part of Apple-oriented chat groups you can't switch to Android without losing access to those groups
What is an Apple-oriented chat group?
No. Why would it?
> I don't know what you mean by you cannot substitute Messages with another app.
On Android, if you don't like the SMS app you can replace it with another app that has all the same functionality (and more). Does Apple let you do that?
> What is an Apple-oriented chat group?
Please engage with the discussion. One that uses Apple's proprietary SMS extensions, obviously.
https://techcrunch.com/2022/03/24/dma-political-agreement/
As a user I cannot see any downsides.