I largely agree, but I'll take the opportunity to fill in some of the other gaps in the conversation.

I didn't mean that you could 3-D print tiny laparoscopes or even visible-light metamaterials; I meant that you could 3-D print machines for making tiny laparoscopes and visible-light metamaterials.

I agree that FDM-like 3-D printing is not currently attractive for feature sizes many times larger than the nozzle size. You'd need printers with thousands or millions of "hotends".

With respect to biological applications of 3-D printing, I think you're overlooking the part of the iceberg that's currently below the waterline of economic feasibility. Biological applications of 3-D printing are frequently highly-price-insensitive one-offs that cannot scale because people don't even consider the things that will become possible when prices drop by a factor of a billion or a trillion.