Ah, but if you read my entire post, you only answered part of the point made. Henry's law seems a straw man in context.
What
@WhistlingBadger noted there is important. A lot of aquarium fish are in terrible shape. When I started up the very powerful laminar flow pump in my 120 of rainbows, I had to ramp it up in 5 increments because the poor fish couldn't swim anymore. After a few weeks, they were active and strong moving in very natural currents for their species. They look healthier and are like different fish now.
When I kept Geophagus argyrostictus in usual Geo conditions, they were downright nasty to each other. I lost a few to violence. A friend who had them in with a high flow pump (because he had caught them in rapids conditions) had zero aggression. Lesson learned.
You ducked the behavioural issues, and the effect water movement combined with changes has on aggression.
I mean, my puppy gets oxygen and clean air along with a good diet, but I also let her go for runs, and walk her a lot on a leash. Like a dog, an active fish needs activity, and an unfiltered tank doesn't offer that. I have a tank of lampeyes I was in on catching 2 weeks ago, in Gabon. The stream was hard for me to walk in, and I am reasonably fit. It was rushing water, and the fish were found racing in the flow's edges. In another stream, I held my net in the highest flow and let the beautiful lampeyes rush into it. Would you keep those fish in non moving tanks? If you do, good luck with it.
For their shortened lifespan, they'd hover and droop, listelessly nipping. Here, they are little bolts of electricity in constant movement against the current, looping aound and setting up again. That's what I saw in the rivers I found them in.