The PDP-11 is definitely still in use today, thanks to its unique and strong build. It is still used to power a GE nuclear power-plant robotic application — and will do so until 2050.
Technically, due to its potency, it is still used by the US Navy in its ship radar systems and by Airbus SAS. There are also rumors that it is part of the set up in the British Atomic Weapons Establishment.
https://history-computer.com/dec-pdp-11-computer/