3D printing does not end on PLA, PET-G, and TPU filaments. Yes, they are great and work just fine for the majority of cases. However, there are more options than just the basic filament types. Polypropylene (PP filament) is one of them.

Strong, but not stiff, can be used to make hinges, enclosures, and boxes. During the impact, it deforms but with less "spring effect" that TPU filament has.

The main problem PP filament has is that it's rather difficult to print. It likes to warp and sticks almost only to other Polypropylene elements. Good luck trying to glue it!