The thing is, to get a pen right, all that they have to do is license Wacom EMR/Samsung's S-Pen (Samsung owns a 40% stake in Wacom, hence using their stylus tech).
Styluses w/ batteries/capacitors were okay once upon a time, but Wacom EMR "just works" and makes my life simpler/nicer (I couldn't count how many styluses I have around my house/in my bags so as to allow me to use my Samsung Galaxy Book 3 Pro 360, Galaxy Note 10+, Kindle Scribe Coloursoft, and Wacom One display (attached to a MacBook).
EMR patents and design specs expired. It's free. China's tooling simply hasn't caught up, because the output doesn't have to feel or work good, it simply has to look good in a kickstarter. Conjecture: I feel like this is like half the reason styluses as a technology are dying; the other half is the untimely death of the resistive display.
Bring back resistive touch!