Teflon tape is a lubricant, not a sealant.

Not hardly. Teflon tape is used on gas valves on high pressure cylinders.

That has nothing to do with how it works.
Teflon tape simply allows the threads to slide and deform until you get a metal
to metal seal. Teflon is used because it is slippery, not because it seals
well. Pipe dope is grease.
The pipe threads are tapered and that is what seals. It is also why used pipes
don't go together as well as new ones. If there is a sealing function it is on
the microscopic scale. It isn't like a washer or gasket.