IIRC, Twenty to thirty years ago it was estimated that the cost to bring a plastic model kit to market was something like $1000USD PER PART. This included designing the part, cutting the mold, injecting the part, packaging (including box/box art, instructions, decals), distribution, and profit margin. This was with CAD/CAM of the day.

Pit road addressed this with common small parts trees. Large production runs also help amortize the cost per part.

Modelers have demanded more detail with more parts (More $$$)

CNC has helped address some of the costs in milling the tooling dies , but they still require human finishing

Lesser known subjects have less sales potential. Yes, the 500 people here know of the WV, but how many want one at what price point. I was told by a friend at Tamiya-USA that Mr Tamiya and the board were concerned about the initial sales of the Fletcher. No follow up square bridge was ordered. Even though long term sales have covered the costs, they saw that sales numbers did not meet expectations.

A 3D Kit can be designed and produced to address a limited market. A unit cost may still rival that of a mass produced subject but the manufacturer is not saddled with unsold inventory.

I find that cutting the print matrix to be calming.