Computers/Software also are nowhere near self-sufficient and need an incredible amount of supporting infrastructure for manufacturing, maintenance, and electricity. The minimum infrastructure to manufacture computers and keep some software running (mining, intermediate products, lithography, electricity, etc.) probably can't be further compressed than the size of a large city, which doesn't just need to make computers, it also needs to maintain everything that makes computers. The supply chains are incredibly complicated and require a huge amount of diverse resources that need be sourced and refined. Calling this "fragile" would be the understatement of the century.
On the other hand two humans in the middle of nowhere can keep the species going indefinitely.
Software running on a piece of plastic and silicon is not going to win a war against humanity anytime soon.