A drive train which is clean , lubed , has well adjusted derailleurs , good chainline in gear and parts not worn down is fun . It's fun to ride. No weird noise. It feels efficient. The feeling is more "connected to the bike". If something is missing in this equation something feels wrong. To the OP , try a bike with a nice drivetrain for 5 minutes and compare it to your bike. Is it possible you have gotten used to it?
A oil free drivetrain doesn't feel too wrong. Not compared to some overlubed dirt magnet. These should wear down faster than the squeaking chains imho. I think a clean oil free chain should squeak. So your chain still has internal lubrication and or dirt which makes your chain not squeak. If you think the chain is ok there should be not too much wrong with it. Keep in mind you could ruin the drivetrain and cassete fast if it's real bad. Lots of people cycle around with the worst chains and could care less about that. They still get forward.
You have derailleurless bikes. Look into a chain case. Then you don't have any reason not to lube your chain. I know they look ugly and maybe not like racing.