It amazes me that in almost every single article of this kind, there is this huge leap from binary adder to "computer as a bunch of labeled boxes", where these boxes mostly describe the data-path and all the control and sequencing is omitted. I think that most people after reading this kind of description will still think that it is some kind of impenetrable black magic (I certainly did for a long time). And it is not and somehow showing how one could build state-machine sequencer out of register and some logic is not that hard nor complex.
Here is project which gets you from relays to assembly language. With careful design (one cycle per instruction), you do not need much control and sequencing logic:
