The fact that the battery drain has gotten worse with the final iOS 17.0 version is what really made me suspicious and why I wanted to see what others have experienced.

Yeah, exactly my point. I'm not saying they break things or make them unusable. But it does seem clear that they detune software to get a mix of slightly better performance on the next gen (below what the hardware improvements suggest) and significantly worse-than-possible performance on older devices to try and force upgrades.