[ffaser5gxlsll]

Regular PLA is actually stiffer than PETG/ABS, but it's more brittle (so has less impact strength) and a pure formulation has a lower softening temperature. It's generally not suitable for parts that go under the sun, unless it's some other formulation such as some HT-PLA variant, in which case it's actually a good choice for parts that need to be thin and stiff.

Under most cases, you won't get the same inter-layer adhesion with ABS, so while you get better impact resistance, under most circumstances PETG will yield more durable parts that won't delaminate under the same stress conditions. For outside use under the sun, you should use it's cousin ASA.

To respond to the OP.. 3D printed parts can be incredibly durable when printed correctly. The parts need to be designed for 3d-printing in mind, like most other manufacturing methods. A 1cm-thick 15% filled PLA slab that has been printed vertically might be easy to snap in half with two hands, but it becomes almost impossible to break with bare hands when printed horizontal, and requires a saw to be cut when filled to 50%+. And this using consumer-grade printers.

I'm using 3d-printed parts for work and at home, some in use for almost 7 years at this point, and the only telltale sign is the layered look.

The rods in the design are not 3d-printed, which makes sense (most plastics would be too flexible, and 3d-printing a rod is always more expensive).

[terribleperson]

You can get excellent inter-layer adhesion with ABS, if you crank temperature up and disable cooling.

I print on a Mk3s in a photo tent and have had no trouble eliminating layer failures as an issue.