I would merge a couple of them, and use a single messaging application that work on my phone and computer.
ARE YOU DAFT?
No! That is exactly what no one except rare cases like you want.
I think you underestimate the number of people who would like the ability to merge at least some of them. And again, it wouldn't FORCE you to do it if you don't want to.
I want them separated on app level.
What is next? All Excel sheets need to be opened in Word? All Word documents in PowerPoint?
Is it really so damn difficult to grasp that normal people want message apps separated?
Except that Excel and Word are not replacements. Most people see Signal, Whatsapp and Facebook Messenger as replacements, and "normal" people don't want them to be separated and would rather use 1-2 apps instead of 5-6. But who care if they don't? Maybe only 10% want interoperability. That's still enough to do it, no mater if you personally like it or not.
But I want a message sent by skype to end up in my skype and not in an universal messaging app. What the fuck, are you a moron?`
You are the idiot who fail to understand a basic conversation. So I get it now, you are just too stupid to understand why interoperability would be a good thing.
If every message I receive ends up in the same messaging app, because I would be to lazy to somehow configure the universal app to reject the messages and route them elsewhere: then I HAVE TO CHECK EVERY DAMN MASSAGE INDIVIDUALLY IN A TIMLEY MANNER TO NOT LOSE AN EMERHENCY EVENT.
If it's so important to you to have them separated, you'll take the time to configure them that way, won't you?
And this is assuming the merging is done by default/automatic, which likely wouldn't be the case. But let say I prefer it that way, why couldn't I configure my whatsapp messages to be forwarded automatically to my favorite messaging app so that I don't have to install and monitor my whatsapp messages separately?
Also most good applications can be setup for distinctive rings for different contacts. Some of them can be your emergency contacts if you want.
It does not make any damn sense to force Apple to route every daman message app into iMessage.
No, what we want is to force Apple and others to be interoperable, so that I never, ever have to use iMessage and 99% of the other messaging apps that I don't care about.
That makes iMessage completely useless
Please stop giving arguments in favor of interoperability, this is supposed to be my role ;-)
If iMessage is your preferred application, then you should be able to create 5 different iMessage accounts, one would be urgent, and the other less.
And you could get a different notification (or no notification at all!) depending on which account you've been contacted on.
Your point is moot. You just don't get it (yet).