Moreover, there are hardware cryptocurrencies nodes such as Casa, Lux Node, myNode, Lightning In A Box the devices that only process transactions on the Bitcoin network.
Like I said in another post, I'm very excited about the possibility of ARM-based embedded Bitcoin nodes. Not the ones running on Raspberry Pi (it's not exactly user-friendly), but if someone created a device that you could just connect to an Ethernet port and power on, as if it were some mobile router, then that would be very cool.