This comment betrays a lack of understanding around 3d printed firearms.
Of course there are your (nearly) fully plastic single shots like the Harlot that fire small calibers and dont always last long.
On the other hand, there’s plastic lowers (the only part considered a firearm and thus the onlynpart that needs to be bought through an FFL) for AR15s that use off the shelf plumbing supplies for the pressure bearing components.
The files are readily available and able to be printed on low end FDM printers with little adjustment and troubleshooting completely bypassing the need to purchase a firearm from a dealer.