Feel free to replace made-up with self-inflicted, that might be more correct, fair enough.
I do experience the human aspect, and have 4-5 different chat programs installed, which is not ideal, but it is just simply can’t be expected that everyone uses the same stuff. I just remember to use Telegram with friends X, Y and Signal with W.
We can certainly expect the 4-5 different programs to work with each other though. It's even happened before. For a brief period of time, AIM, MSN, and Yahoo all had some kind of interoperability with each other.
The sad thing for me is that even though almost all my contacts have iPhones, the lowest common denominator effect means everyone ends up using WhatsApp to allow everyone to join. That’s definitely a worse outcome
My biggest pet peeve is when people have an issue that doesn't affect them so they need to declare it as "fake". Just because you don't feel the problem doesn't mean "it's a made up issue".
The following are simply facts:
1. In the US, among iPhone users, iMessage is by far the dominant messaging service.
2. Among certain socioeconomic groups in the US, iPhone is by far the dominant mobile phone. I have been in several friend groups where there was at most 1 other Android user.
3. In group chats, not only does the limited functionality for Android users make it harder to converse, but the presence of a single Android user can break the experience for everyone (I've had messages randomly not show up, abysmal video quality, etc.)
So while I would absolutely love it if other people would switch to Telegram or WhatsApp or whatever, you try telling a group of 10 people "Hey, can you all switch the messaging app you are familiar with and use all the time so I don't feel left out?" If you think that's viable you just don't understand human nature.
The other option is for Apple to simply make an Android version of iMessage (like all the other messaging apps you mentioned), but they don't seem too keen on that.