I'm gonna be extremely blunt given that I have you in my audience, large streaming media worker bee: It's not surprising in the slightest that you have a bias towards the effectiveness of DRM when your livelihood depends on it. The fact that the unit-cost is "relatively insignificant" is simply a continuation of the straw man argument that props up the entire notion that DRM is somehow cost effective. I don't personally think you are a jerk or anything for working your job, but I can say that I would not personally find it fulfilling to spend my own career on something with such diminishing returns. I guess all of those insignificant expenses add up to some good money in the end, at least in someone's opinion. The incentive to continue burying the failed promises of DRM and keep it propped up as long as possible is evident though; the story really hasn't changed in the 30 years or so that I've been following it.

The lack of a "save video" button in the player app is the most effective means to prevent the average person from distributing the content. By your "lock on the door" analogy, a UI that does not allow the thing you don't want your users doing is providing more or less equivalent protection to the DRM. It doesn't matter how many locks you put on your door if all the attacker needs to get what they want is to look through the window. Why continue to invest in the additional technology if it is not actually adding significant additional protection? By the time any user presents a willingness to do anything at all to circumvent your standard software interface, you have lost; the user will succeed. Plugging in a $30 recorder and pushing the button is all it takes, and all the sweet cutting edge secure enclave crypto quantum DRM in the world cannot prevent it. How many of those 20k illegal streams you cite even bothered to break the precious DRM? My guess is zero.