There is places and things that work for 3d printing. Very small scale manufacturing. Prototypes. But actually selling those is somewhat hard and not scalable market. And home printing... Yeah that sounds like hobbyist to me with corresponding market.

On other side you get to complex topologies and very specialised parts. Again pretty hard to scale and limited demand.

In the end it is manufacturing and manufacturing is huge. But also generally does not have great margins. It has lot of competition. So 3D printing would end up there with others say makers of CNC machines, various presses and so on. Multi-billion dollar industry, but not tech.