Dude, you realize that in 2022 right after the invasion started Ukraine freely gave assault rifles and ammo to every man and woman who wanted them. A large part of why the initial invasion attempt failed is because of a quick decentralized defense. But that only goes so far. Ukraine is up against an enemy that is perfectly able to mass huge amounts of force in a single location to break through. Ukraine needs to be able to respond to that. And that's not possible without wider scale coordination. Re: "complete fucking genocide", that's exactly what Russia has done in Ukraine. In Bucha civilians were simply mass murdered by the hundreds. Russia has no qualms responding to resistance by simply flattening cities with artillery and airpower. Hell, just the other day Russia used multiple cruise missiles to flatten an apartment building, killing 30 people. Speaking of, how exactly are "3d printed guns" going to stop cruise missiles? 3d printed drones actually do stop shahed drones. But again, that's not some decentralized effort. A big part of making that work is centralized organization: you can't put AA assets everywhere. You need top down organization to figure out how to move them dynamically to be in the best place to intercept each attack.