It doesn’t seem like you’ve read much about insurgencies and rebel groups. It doesn’t actually take much firepower to inject enough chaos into the system that you cause issues with traditional militaries. One person with a rifle could keep a FOB alert and wasting resources for a couple of hours in Afghanistan. IEDs placed by individuals or small groups caused absolute terror in Iraq.
These types of things are unlikely to “win” a war. But if you make it costly enough, the other side will decide it’s not worth fighting. The point is not to engage in head-on combat, that’s suicide.
Or hell, look to the tactics of some of the rebels in the Revolutionary War or the Civil War.
Sure, if they’re willing to just destroy everything then it’s less of a solid tactic. Will the American military be so willing to just destroy the places they grew up in? Perhaps. Will they be willing to shoot the neighbor they grew up playing with? Perhaps. Will they be willing to level the school they have so many fond memories of? Perhaps. And if so, then yes, that’s game over.
The US military has historically been pretty terrible when it comes to insurgencies. But obviously they haven’t been fighting in their own backyard.
It’ll be interesting either way. I sure hope it doesn’t come to pass.