Worth noting that GPIB is still very common in labs and present in modern lab equipment that's still in production. Tek's AFG31000 is one example but there's countless more.
Mil/gov customers are still die-hard GPIB users and that's a major sector for T&M sales.
Indeed. Keysight's top-of-the-line long-scale DMM, the 3458A, was redesigned (chiefly for RoHS compliance) in 2019 and the GPIB bus remains the only means to remote control that instrument.
To be fair, that's a small redesign of a 40 year old design (everything is still through hole, for example).
The AFG31k is a brand new design from the ground up and it still has GPIB! And it's far from an isolated case, GPIB has a strong network effect, pun intended.
But Linux doesn't run on a PET-2001