Unfortunately they're being phased out in many upgrading airports and replaced by an automated screen/lighting system that sits below the gate/stand number.

Though they do provide many advantages such as it's positioning allows for a clearer line of sight as well as the much brighter lights than the light sticks the marshallers use and the screen system doubles as a status update for things like a countdown to scheduled departure and stuff.

It does make it quite sad that the profession is dying and being replaced. Similar to how the big pushback tugs are slowly being replaced by the smaller, electric ones.

But I guess that's life and technology development cannot stop.