See, that's what I find interesting. Interesting because I'm not an engineer and don't understand the technical side, but I've experienced the opposite. More than once.

I rode a friends single speed bike and if I just rotated the cranks lightly (kinda floating to match the current speed) things felt and sounded OK. But once I started getting on it, it felt tight/rough and sounded nasty. I checked the chain and it was not worn and was well lubed. Tight vs loose spots were there but insignificant. Rifle sighting indicated a satisfactory chain line. I checked for slack. I could move the chain up (from center) about a quarter inch and down a quarter as well. So technically, 1/2" of slack existed. But it felt tight, not free to move up and down. I adjusted it to my usual amount of SLOP (impossible to derail, but very slack) and I couldn't reproduce the noise or the rough feeling.

Another friend later complained about a noisy drive train after installing a new chain. The above story played out again identically.

Dunno. Shrug. Chalk it up to SS phenomenon I guess?