@joe2009 One more thing to say:
Interestingly the iOS-App "Opera GX" ist obviously able to store a webpage as a PDF-document!
And my first tested resulting PDFs are pretty readable at all, I think!

(... remains the question: Why not in "normal" Opera-iOS-App?

@joe2009 I agree to 100%!
In some way it's a pity missing this option in iOS-Opera!