You just can't prove that... Maybe because is by far not true.
For example, you can create an app that only uses LAME + VideoLAN encoders and supports two of their formats, MP3 and MPEG4 nothing else, cause you're sure those work on the hardware you're building, that's exactly what Apple does, and Ubuntu, and Windows.
Just use your LOGIC how the hell is an open protocol the reason why stuff breaks? If everyone is looking at it and it goes through a lot more review than closed standards, they're the reason why we have the internet and how it works.
Contrary to what you believe on, Apple actually uses tons of open protocols and standards, they made Webkit what it is, that's free and open source, they still work on it as far as I know, they have their fair share of closed ones too, but open has worked for them pretty well.
HTML is an open standard, try writing a strict HTML browser that fails on non-standard pages and then surfing the web. There is a huge difference between using HTML files internally generated by a process you control and trying to read anything calling its self an HTML file.
The same applies to MPEG4 there are plenty of files that work on one player but not another. EX: Wait you also want to open an 8k MPEG4 file on a phone?
PS: I wish everyone that suggests open solutions actually needed to implement one. Generally, when people say open solutions they really mean leverage some huge chunk of code that someone else wrote, or let me leverage your hardware and software for free.