I’m trying waxing my chains this season using Molten Speed Wax. I’ve been alternating 2 chains on my road bike. They get switched when they start to get noisy. That was supposed to be at 400 miles but 200 miles is more like it. To be fair, I may not be heating up the wax quite hot enough to fully penetrate the interior space of the chain - I’ve spoken directly to the Molten Speed Wax person and he was very helpful. The clean aspect of the wax is real. It is nice when you can touch the chain and have minimal dirt come off on you.
Which got me thinking: why hasn’t anyone developed a completely lube free chain?

I started thinking about the little sealed bearings that are used on woodworking carbide router bits. They can be minaturized quite a bit I would think. Maybe someone in the bearing industry can pipe in here? You could have each “roller” being the same outer dimension as the roller on a standard 10 or 11 speed bike chain. The “roller” would be the outer part of the sealed bearing. The interior could have permanently sealed stainless or ceramic bearings in it - do they make them this small? No oiling, no waxing or any kind of servicing would be needed. I realize we are talking about ~114 links so this many bearings would go into each chain.

Obviously the cost could be prohibitive for a chain like this. But would the cost really be that bad? I mean - the little bearings, sourced from India or China or whatever international manufacturer could produce high volumes of them cheaply could be less of an obstacle than imagined. Also, depending on the performance of this chain - increased cost for a longer lasting, lube free chain would be justifiable. I would easily pay $100 or more for such a chain.

Maybe it already exists. Maybe it could be manufactured with newer engineering materials to be even lighter/simpler/more durable/quieter, etc.. Maybe the Gates belt drive could be developed for derailleur/multi-geared bikes?
I’m just thinking out loud here and hoped to collect up some ideas about next gen chains!

The trouble with tiny bearings is that the size of the contaminants a bike sees doesn’t change.
The size of particle that a cup&cone bb would hardly notice is a considerable issue for an outboard bb and would be instant showstopper for the size you’re talking about.
You’re likely to end up in the ”operation successful, patient died”.
Meaning succeeding in what you wanted to do, but failing to achieve the desired outcome.
A more doable way of avoiding/reducing chain care is probably an adaptation of motorcycle tech, where o-rings are used to seal the bushings off from the environment.
And to accept to use an IGH.

Are there any current chains out there (for derailleur bicycles that is) that use O-rings to seal the bushings?

How about a chain that had micro (micro again) “grease guard” technology that could be topped off before a ride by pumping a tiny bit of clean grease into each bushing through a tiny grease guard fitting?

Thanks for the reality check. The little bit of wax build up on my cogs and chainrings seem to quiet things down a bit with my waxed chains. But “wet lube” has got to be the quietest.

The roller is just one of the chain’s moving parts. The plates also oscillate on the pins to allow it to bend. The tiny cartridge bearings suggested by the OP would do nothing for that wear point.