This article from the same author is also a great read:
Marc Andreessen is a philosophical zombie
and reinforces how out of touch these people are from reality due to their lack of intellectual curiosity and the cavalcade of equally vapid sycophants that surrounds them.
The gadgetbridge project is currently working on supporting (optional) network access, so integrations like this should become possible.
If you can charge it outside of the controller than this opens up the possibility to have multiple batteries which you can swap between. I don’t think that is the case going by the article, however.
Look for a watch supported by gadgetbridge and then just don’t connect the watch to the internet or use the official apps. Although Garmin at least allows you to prevent sending personal data so you can still get firmware updates, which is useful because much of the functionality is on the watch itself.