It is very effective. It's not necessarily supposed to change your mind about unions. It's about scaring people who might consider unionizing. It's a subtle way to tell workers "don't try any of that shit, or else. Also we're telling your coworkers to snitch on you, are you really gonna risk it?". They want to convince you you're in great danger of pushback and getting snitched. That's especially true for the training videos.