It is not an oiled bearing, the thin bronze/brass type bushings have a solid lubricant built in. From the appearance it appears to be MoS2. The Krytox grease is inert and proven to be one of the best lubricants to prevent galling.
Stuff is so pricey in quantity that the main user is probably the government.

I did hours of research and contacted manufacturers of specialty lubricants.

Galling is the primary wear for the tensioner pivot bolt.

I agree that a bouncing belt will definitely wear the assembly much faster. Luckily with replacing the water pump and installing a one way pulley on the alternator the belt has no detectable bounce while the engine is running.

I do mess up now and then but I think I'm one of the few that got over 300,000 miles on a V8 Range Rover by doing most of my own maintenance. Still running good when I sold it but had some serious corrosion on the inside of the front cover. Had to have the aluminum particles from corrosion removed from the radiator cores from time to time. Would have used G-05 if I had known about it and if it was available in the early 90's.

I thought Mercedes parts were expensive until I had to buy a few Range Rover parts. The dealer wanted over $300 for a seat adjuster switch, I knew it looked like a Mercedes part and sure nuff Mercedes had one similar for $80, worked good after a bit of plastic trimming.

I'm definitely a goof ball from time to time. I was driving the Range Rover from Lincoln NB to Dallas one late summer day and noticed a farmer harvesting acorn squash and filling up huge palleted boxes. I love acorn squash and turned around, talked to the farmer, bought a big tote box full, enough to fill up the passenger floor boards and the back area 1/2 way up on the glass. Had over 1/2 of it sold at farmers markets and veg stands on the way south.

Time will tell but the belt is so smooth now I think the assembly could almost be welded in place.