I am on-board with taking multiple strategies, any political strategy that categorically ignores electoralism or militant direct action are likely making some kind of strategic error. However, this zine does not take that position. Some more context around the quote you provided, first it is under a heading:

Rejecting settler colonial authority, aka not voting.

The surrounding context of the quote:

Voting will never be “harm reduction” while colonial occupation & U.S. imperialism reigns. In order to heal we have to stop the harm from occurring, not lessen it. This doesn’t mean simply abstinence or ignoring the problem until it just goes away, it means developing and implementing strategies and maneuvers that empower Indigenous People’s autonomy. Since we cannot expect those selected to rule in this system to make decisions that benefit our lands and peoples, we have to do it ourselves.

They are saying we shouldn't ignore the problem that voting is supposed to reduce harm from, but directly address it with direct action. It is not saying we should still vote and participate in electoralism. Nowhere in this zine is it implied voting is any form of legitimate political action, and everywhere it implies it is 1. unhelpful and 2. wrong.

For example:

Consolidating the Native vote into a voting bloc that aligns with whatever settler party, politician, or law that appears to do less harm isn’t a strategy to exercise political power, it’s Stockholm syndrome.

To organize from a position that voting is an act of damage limitation blurs lines of the harm that settler and resource colonialism imposes. Under colonial occupation all power operates through violence. There is absolutely nothing “less harmful” about participating in and perpetuating the political power of occupying forces. Voting won’t undue [sic] settler colonialism, white supremacy, hetero-patriarchy, or capitalism. Voting is not a strategy for decolonization.

Even if I agree that voting won't undo colonialism, white supremacy, patriarchy, and capitalism it is clear that voting can reduce the harm of this system by avoiding some electoral outcomes and prioritizing others. This zine would be in a much stronger position if it were willing to take a slightly more nuanced position that voting should merely not be the top priority or focus for political action, which seems exceedingly reasonable and well grounded, but instead it argues the absurd position that voting and participating in electoralism can show any benefit or lessen any harm.

I can understand frustration with liberals and the dominant prevailing political culture in the U.S. which makes voting seem like the only legitimate form of politics, and so perhaps they feel the need to exaggerate or take a more extreme position as a counter-weight, but it needlessly weakens the position and will only effectively work as rhetoric for insiders who largely already agree and who will simply entrench themselves in symbolic positions like this against good sense, which primarily fractures the left and makes coalition-forming more difficult. I'm not calling for blind, authoritarian left-unity but politics are too important to not be smart and strategic, and I don't see arguing for not voting as the zine encourages helps on any front. The value and necessity of direct action can be demonstrated adequately without making a case that voting cannot reduce harm.