I’m every stereotype of queer and ADHD and autistic, when it comes to posture. Good for you that it serves you well but my body needs back support and a thousand places to put my legs :)

Is this for real? Can people really sit on a piano bench all day?

It's totally for real, and I stand up and walk a little every hour or so, or I'll get tired and start slouching. WFH eliminated my chronic back pain, and I credit the bench.

As I understand it, the key is the good posture. My back pain was caused by weak lower back muscles. Maintaining good posture exercises those, where comfy chairs only relieve the immediate discomfort at the cost of long-term health.

Not much different than a yoga ball as far as that goes is it?

Yoga ball is better and will train back. Allows for improved movement and spreads pressure. Might need something underneath to lift it up a bit.