PTFE tape on a shower arm’s threads

PTFE tape is tidy and easy to apply, but I’m not sure it’s the right choice for every threaded shower connection. Does the answer mainly depend on whether the threads are tapered pipe threads or a straight-thread connection that seals with a washer or gasket?

I’d also expect the fitting material and manufacturer’s instructions to matter. When is pipe-joint compound a better fit, and should tape and compound ever be used together on these fittings? I’d rather avoid making a clean-looking joint harder to assemble or more likely to leak.