I believe sextants will be obsolete the day fuses are obsolete. It has happened to me that fuses have blown and that I have, for a shorter of longer period of time, been without current. I think that this may happen again. Therefore I still use paper-
charts,
compass and sextant. I have even printed out, by means of Microsoft excel, a sine and cosine table for each 1/10° between 0° and 90°, in case my pocket calculator looses current, so that I can solve the celestial triangle by calculating with pen and pencil.
Celestial navigation is not hopelessly difficult. It is, after all, a question of solving the sides and angles of a triangle. Two points are known, the (North) pole and the position of the sun (or any other celestial body) the third point, you own position, is assumed by dead reckoning.