Just thinking about a typical household these days, say a family of four. That's 4 smartphones, say 3 laptops, probably 1-2 tablets. In my house theres a lot more because every AA, AAA, etc. are lithium ion rechargeable anymore which includes video game console controllers, physical remotes for TVs and other devices, and so on. Also everyone owns a tablet of some sort and a laptop. Not saying these will create a humongous exploiting by themselves but each and everyone is a potential ignition source to start a real fire. You'd have to isolate and protect all of these things, regularly, to really add fire protection to your home.