voxel

copyright will eventually expire after your death

and cc nc does not prevent derivatives, just profiting off of them without explicit permission, which is not that big of a deal

the author can still sell the work, the NC prevents other people from profiting off of it without explicit permission (this does not prevent exemptions, work can still be sold under cc-by-sa as an exemption)

or CC BY-NC-SA (the non-commercial-use-only one)

they do collect usage stats by default though.
which include typed sentences passed through their ai model and words usage counts.
it can all be turned off and gboard seems to respect these options. it doesn’t access online services unless requested with these options off.