Of course they can. In fact, most of the industry counts on them continuing to hear every veil that they suggest is lifted with every tweak or upgrade.
I'd like to see a single one out of the many you are standing with to step out from the crowd and demonstrate what they hear with a valid test.
Lots of people saying 'ME TOO!!' doesn't turn it into evidence.
Indeed BDW you are completely correct, the industry is BUILT on a bunch of people imagining sonic differences and the ephemeral nature of sound. Disproving it takes effort so it is easier to believe the illusion.
Here is a couple of concrete examples I have previously explained here
https://www.audiosciencereview.com/...ds/revealing-member-stories.9947/#post-268910 These clearly show that people imagine the sonic differences they expect or want to hear.
"I have 2 more...
On a couple of occasions I changed the LED on the front of an amp (multiple versions) from blue, to yellow or red. Sighted testing by others (multiple copies of the amp available) had listeners saying the amplifier with the yellow/red LED sounded smoother and warmer... There was no circuitry difference. This was for a bet with an acoustics friend (he won).
With a friend who was a die-hard vinyl fan who would tell me that digital audio sounded bad/"cold"/sterile blah blah, I once digitised one if his favourite albums and played it back swapping between the digital and analogue versions. He confidently picked the analogue version as sounding better etc. I then said, "Oh, sorry I had the leads swapped, that was the digital version." to which he cried out, "But now I don't know what I'm supposed to believe!" The 'supposed to believe' bit stuck with me... Now he ignores the hifi press, and freely admits that digital audio sounds better, he even likes streaming! But he still often plays vinyl, loves the covers and his several thousand records for what they are - and who wouldn't?"
EDIT: I will point out that I claim no superiority in this matter, and neither do others. It's just that I am aware of how my mind works, and all people are wired this way. I have fooled myself mixing a song in a studio, adjusting the EQ a tad, only to look across the board 20 minutes later to see the EQ bypassed on that channel!
It happens to all of us, it's how we are wired, and that's why we have process to avoid these biases (level-matched, blind tests etc). Many others are similarly careful and have been fooled, Bob Katz (mastering engineer) tells a story where he thought a DAC was SO much better than his old one, until he matched the levels - then they sounded the same...