It depends on material type, print settings and design itself. While injection molded parts are usually stronger, 3D printed parts can survive a lot of stress if built correctly (some printers are built from 3D printed parts for example). But you are right, OPs tubes might not survive for too long (it will break between layers most likely). I wish it survives for many years tho

On the other hand, 3D printing is not only used to build better and cheaper parts, its a hobby for lot of us. The ability to imagine, create a 3D model and build the part at home makes me feel powerfull. Its almost always better (cheaper, stronger, faster) to use other technologies or just buy something, but where is the fun 😄