Memes of Production

Seems like you just do not understand Anarchism and are trying to compare it to current society, which it is fundamentally different from and unable to make direct comparison to.

They can try to rally people but the rest of society will rally against them in kind to maintain their autonomy.

MAGA exists because of our current institutions reinforcing those beliefs. Dismantle those and those beliefs disappear with them.

The system already dictates our society. It isn't about "should" but "will". We currently live under a society where authority comes from the top down and the populace must listen or be forced to capitulate by threat of violence from the police. People gain that authority through manipulation of social biases to be granted position labor power to command over the above mentioned society. This is directly due to our institutions being structured with respect to hierarchical power of authority.

In Anarchism, you wouldn't have any police, you would have a completely and fundamentally restructured society that doesn't allow for individuals to garner hierarchical power and exert authority over others without direct and mutual consent from the parties involved.

Your hypothetical isn't a "utopian paradise" if 5 people feel incentivised to take your fish instead of just fish themselves. Why would they? They would understand that if they do so and gain a reputation for being thieves who take things by force then no one will want to associate with them, and thus they will lock themselves out of the collective benefits of society.

Go read more if things are not clear. Read Kropotkin if you want dense theoretical explanation, read Graeber for a historical understanding of how these powers came to be and the alternatives that are possible. Many other names exist as well such as Malatesta, Bakunin, Lucy Parson, Emma Goldman, etc...