The video you linked was done exactly like that to show the absurdity of the very thing you are just arguing

Yes, why possibly could I have posted the fucking video right before making the point that teenagers do not properly engage in the conversation? Amazing.

Why would someone be repelled away from the left because someone says antisemitic tropes are bad? It is just fucking stupid.

Because 14 year old kids are fucking stupid. You're trying to have conversations with audiences that are not even ready for it. The conversation is held in a way that does not even get the point across, either. "antisemitic tropes are bad" is not what is reaching the audience, "Pewdiepie is a Nazi" is what is reaching the audience.