If a mathematician generates a 12 word seed, memorizes it, derives a wallet address using pen and paper in a private location, then goes to another private location and sends Bitcoin to it, then burns the pen and paper, I can't think of anywhere else the keys would be stored except their brain, so no microchips are needed to custody Bitcoin.

I wasn't taking it to that extreme though, I would accept microchips being involved as long as the microchips are in devices the user keeps safe and touches with their hands.

Lightning seems to go beyond making you use microchips, to the extent of making you use random microchips you have no control over, e.g. the servers and switches managing an internet connection