I think there's space for two spintronics. They are different enough that I don't think anyone will get confused.

Agreed, it's an unfortunate namespace collision. Spintronics is a really cool area of physics, with decades of research.

Electrons have spin. Although 'classical semiconductors' exploit the electron's spin via the Fermi-Dirac distribution in transistors, the actual sign / direction of the 'spin' is ignored in everyday electronics. Making use of this available spin degree-of-freedom opens up a whole wealth of new possibilities.

Spintronics has already revolutionized certain industries (eg, GMR in magnetic hard drives), and there are further open areas of research (eg, spin as qubit basis states in quantum computers).

The main difference is that spinning gears makes sense, whereas spinning electrons do not!

(I kid of course. Spin in physics relates to inherent angular momentum. If you wonder why that exists, you may also want to wonder why mass exists.)

Intrinsic angular momentum is weirder than intrinsic mass because you can take it out and put it back in - although for most particles you're not allowed to have zero. But you are allowed to take 1 from an electron to go from 1/2 to -1/2. If that is not enough, you can go back from -1/2 to 1/2 by changing your basis vectors. ;)

Further - paired electrons can collectively form the spin-zero singlet state, or spin-one triplet state. In either case the two electrons, which are fermions independently, together act like a boson (eg, Cooper Pairs in a Superconductor).

Addition of quantum angular momentum is really weird.

I don’t know enough physics and haven’t put in enough effort to understand https://arxiv.org/pdf/1910.10478.pdf but it seems intriguing.

I thought complex phase precession was from energy, I don't see how it's related to spin.

Would you say that about Apple computer, or Continental Airlines?

But then, all puns are unfortunate. It's kind of their thing.