For example continuous inkjet printers are used to label packages of many items you buy every day. There's also research about inkjet printing wearable electronics etc. None of which has a lot to do with HP.
A lot of the comments here read like a hobbyist programmer saying “C++ is dead, I haven’t written any C++ in my projects for years and since I’ve switched to Rust, I’ve never looked back”.
Yes, I stand by this analogy because inkjet is that important. The market is doing great and technology is improving at an impressive rate.
To build on your example of continuous IJ presses: more and more applications have lately been switching to drop-on-demand, as those printheads continue to get better (especially piezo IJ) and cheaper (especially thermal IJ).
“Inkjet 3D printing” exists, but it’s something quite different: https://en.wikipedia.org/wiki/Powder_bed_and_inkjet_head_3D_...
I haven’t had an inkjet for 30 years - only black and white lasers. Starting with HL LaserJet 5L in 2000, then Samsung and now Brother (yay for their nice platform independence so they work on Linux).
My Prusa 3D is also arguably spewing a material into a surface so I guess yeah, maybe I should count it as an inkjet as well, though ;-)