3 years has past you / Opera are saying the same thing:
"We don't 'choose' to limit this functionality. Unfortunately there are complicated legal restrictions around distributing support for H264 video decoding, and it comes down to 'we can't give you this functionality ourselves'.
Therefore we rely on others to give it to you. On Windows and Mac, it's the operating system that provides libraries that do H264 decoding, and Opera uses those. On Linux it's a bit more complicated, but it comes down to 'we use what Chromium uses except we can't give it to you ourselves'."
You choose to simple to do nothing about it.
When my boss ask about a task, he want solutions not problems.
Like i said when i install Brave, it has same problem, however when I install ffmepg or openH264, , somehow finds the path to the codes and works.
It is not first time i am writing about this.
I am writing this because i want to keep using this browser.
And when i choose a linux distro i want to choose how i want to install it with .deb / .rpm or snap.
Again, in quotation, you currently are choosing to to limit this functionality instead of solve the problem. 