are we talking tradition., or an actual engineered or logic behind it? Many pipe dopes are adhesive., So yes it initially lubricates when assembling., it makes it harder to disassemble. Because some are adhesive., and some dries., or have a soft set.
In the grand scheme this is a minor thing...
I'm saying a product specifically designed to STAY as a lubricant to prevent sticking together on flanges and threads for things that will later be dissassembled would be Food grade anti seize....
Smarter ways. Many times I had to brush the old dried up pipe dope off of threads to reuse. Try some anti seize....
We probably beat this topic to death