I can't speak for everyone who comments, but consider that many members here have played high school football (and some even college ball). Even in high school football in the '80s, watching game film was (at least) a weekly task. And if your role was to block for others, you learned - at minimum - to evaluate film of yourself executing your blocking assignments. Fast forward thirty-something years ... you apply the same evaluations when watching the blocking of Saints players.
YouTube and social media (esp. Twitter) has made it a lot easier to get at least brief clips of meaningful game film - complete with downfield blocks, backside seals, guys releasing/moving to take a second man out after an initial good block at the snap, etc.. You're right that it's hard to see all the blocking assignments on a game broadcast. I know some people get their hands on All-22 film, and I think (not sure) there is a way to get that film online (Maybe a pay service or something? Or else be willing to wait a few months for it to come out free? Not sure.).