PTFE, often called Teflon in everyday project language, is valued for its very low friction and excellent chemical resistance. It is often the right answer when a part interacts with fluids, sealing systems, or environments that would quickly challenge many other plastics.
The tradeoff is that PTFE is softer and less structurally rigid than engineering plastics like POM, nylon, or PEEK. That means the geometry must be designed for the real service condition rather than assuming every plastic behaves the same way under load.