Anyway, my takeaway is that long term audio memory is a more complex story, it certainly has resilience and differentiation in my experience (but the efficacy for a reviewer who listens to many system will be a different story). Bass is pretty straightforward (watts are good, but current is better, if you'll excuse the vernacular). Stereo image is the complex product of many factors, starting with the recording, but I wouldn't rule out the amp-speaker-room system as contributor.
How do you know this take away is true? Better yet, how can you prove this take away is true? Where is the proof point? At no time did you perform a controlled test like I mentioned in the video, correct? Without it, your conclusions are only yours. They present no value on the topic at hand. Indeed, they go against the consensus of audio research community which has tested these theories.
According to ASR lore, this can be explained by sighted bias. I was (weirdly) biased against my new amp (I know, a bit contradictory).
First, it is not according to "ASR." It is according to accepted audio science which ASR follows.
That aside, no, the problem is not sighted bias directly. Your hearing is elastic. You listen more intently at times vs others. Your hearing system is bi-directional with the brain instructing how your auditory pathways work. This feedback loop relies on the task you give it. Tell the brain that you are testing something new and it will focus more and attempt to dig out detail, listen for transients, etc. And lo and behold, it "hears" improvements even if you thought there should be none. Or be negative. This is why the excuse that "I didn't expect it to sound good but it did" doesn't work. There is no pre-requisite as such although that is also another factor that pollutes the results.
You need to put yourself in controlled tests, graded by others, with conclusions known in advance to see how good at these things. Just running experiments yourself and deciding you were right about this and that just doesn't work. As I showed earlier, audio reviewers performed horribly in controlled tests of speakers. Yet I am sure all thought they were great in telling performance of speakers.
Please remember that all of us also exist in your shoes as well as ours. I like you hear things that later realize where not there. Have this happen to you enough times and you get sober and realize your perception is not what you think it is. That your intuition can be so wrong in audio.
Measurements and understanding of how your electronics work is a powerful antidote to arriving at wrong conclusions. If I perform a digital null that shows your audio device didn't work differently when you upgraded its power cable, then that is that.