WhatsApp has 2B users vs. 1.6B for Apple. Of the 1.6B for Apple there is a group that would not use iMessage, but any other 3rd party application, like Whatsapp.
The fact that you are left of a chat does not make Apple a monopoly. The people in your group could choose to all switch to the same application, of which most of are closed source. I spent a ton of time in APAC and while each country has different most popular chat apps, the group of us that have spent years working together on and off at different companies all agreed on a common chat app. It's just not hard.
I have a few long term friend groups where a member has an Android and the text is green. No issues sending them text at all. The MMS stuff can be broken but that is not Apples fault.
Your argument is Apple once again the same as everyones else, and appeal to everyone be open because it is your philosophical view of things and it would make your life simpler.
Apple is a for profit company. They are not a monopoly on chat because they choose to offer their users a better experience over the standard SMS (which they supported).
I am frustrated with all the people that miss that distinction. They are a private entity and can do what they way within the outline of the law. You can vote with your pocketbook, or run for office and get the laws changed.
Also, the OSS vs non-OSS comment: you cannot take for granted that everyone here comes down on the side of the GPL 100%. There are a ton of us that work/worked at companies that did priority software because that is what made sense for the business model. We do not write software for free - ie, there has to be a method to pay our bills. I personally have major issues with GPL3 when it comes to creating works for a profit company. No major ones with GPL2, Apache, MIT, etc.
