I have a couple of Raspberry pi Zero, and you gave me an idea to start a node on one of it. I will try in in a couple of days and tell you how it works.
Great! Of course do try it, I wish you success, as the more full nodes, the more decentralization, the more reliability and the better!
... and full node earn nothing, maybe that should change, me being a noob looking from the outside in, this does not seem fair
As I understand it, according to the original plan, ALL of the wallets were supposed to be full nodes, so naturally there was not provided any reward only for that. Moreover! All of the nodes (wallets) were supposed to be MINERS as well! And as miners they would have gained the reward!
According to the wiki, a full node does not have to be an "archival node" which stores the whole blockchain and accepts incoming connections.
If your full node keeps the whole blockchain ("archival node" as you named it) it is much safer and better for the Bitcoin Blockchain ecosystem, and your own money accordingly, if you have any real (Bitcoin) money at all.
So if you can afford 160+Gb blockchain then do it! If not, then keep a pruned node.
Anyway, the main idea is having any is very much better than having none.