While one may not track stand at all lights, like all other cycling specific skills, it is useful. The confidence one gains in being able to successfully "do" one and the balance gained from practicing both contribute to a cyclists safety in--and enjoyment of--the sport. Regardless of new innovations in technology, the skills and tactics of yesteryear are always applicable and beneficial to ones riding.
Off the top of my head, some useful skills, some basic, some advanced, that improve bicycle handling & therefore safety in no particular order:
- Riding no-hands
- Leaning into another rider without falling over (aka, rubbing shoulders)
- Riding in a straight line (not swerving)
- Riding close to another rider
- Clearing debris from a tire, front or rear, after rolling through it
- Taking a drink from a waterbottle & returning it to the holder without stopping pedaling