I do find chess magical just in how kind of perfected it is - in the sense that it contains so few simple rules and pieces that return so much complexity. It's basically what any puzzle game designer aims for, but as you say honed over literal ages. It's hard to imagine you would design it the way it is now if you were starting from scratch, but it just works.
Also, for all I said about abstract ideas of chessiness, I think I probably will end up with something mostly following the rules of chess. I think that's fine, as long as you're exploring something that you find interesting about it.