Nothing you described here is a trivial problem, nor a problem that Github has any responsibility to unilaterally fix, nor do they have the tools to do so alrea

Nothing you described here is a trivial problem, nor a problem that Github has any responsibility to unilaterally fix, nor do they have the tools to do so already as you previously stated. If Github were somehow helping copyright infringers, that would be encouragement. What you're describing is additional effort on their part to actively discourage copyright infringement, which is not the same thing.