If you ever opened up a new S&W revolver, you would be shocked at how dry they are inside. Literally, just a dab of light oil on the pins and crane.
At armorers school, years ago, the instructors told us that over oiling and greasing revolvers caused more problems than anything. It turned sluggish, trapped dirt, crumbs, lint, sand, whatever.
The old Dallas PD armorer would get brand new Model 64’s. Lightly cleaned and tuned the insides, corrected timing, and then hosed them down with silicone spray and blew it out with compressed air. He swore the dry lube worked better on a duty gun than anything.
We tinker. We oil, get a new oil, figure it’s better than the last oil, change the oil out, dry fire it, swear it took 2 ounces off the trigger pull, tell our friends, play with it son more, take it apart, see how all the little parts move around....etc.
A duty Revolver sat in a holster. Exposed to all the elements until it was needed.
Same reason most revolvers are oversprung. They were made to go the full 30 years with the cop it was issued to with little or no maintenance. And, they actually did it remarkably well.