Do old cycle lights get dimmer with age?
My old (2007) Exposure race is still going strong, but is totally outshone by my newish Joystick. It should be brighter (480 lumen) than the joystick (400), but appears very dull in comparison. I don’t think it is a battery issue as these are regulated lights (?) so a failing battery should just give shorter burn times.

Maybe the joystick has a more spot type beam pattern so it looks brighter ?

is the torch lens pitted and grimy? diffusion of the beam

Lens is a bit pitted and beam is yellower than the joystick.
Beam pattern could be it I suppose

Read somewhere that the plastic material used for the lens / collimator can degrade over time with exposure to UV – you see a lot of older headlamp covers that have yellowed with age. Maybe that is contributing to the problem.

LEDs do dim with age, especially if driven at/near their maximum power output.

We’re struggling at work, because with old filament bulbs they worked or blew, so specifying when they needed replacement was easy. With LEDs they’ll dim so deciding on replacement standards is going to be interesting.