I think it is similar to what happened to AI in the so called "AI winter", where professionals, consumers, companies and funding in general walked away from AI for quite some time.
We do know that for sure 3D printing will make a comeback for good one day, probably one decade in the future.
I'm not sure that is comparable. 3D printing isn't dead in professional use, research is still happening, has an active hobbyist community, ... it's just the "3D printer in every home" idea that Makerbot and others tried to peddle that's not happening.
We do know that for sure 3D printing will make a comeback for good one day, probably one decade in the future.