Hi Spidey! You made an interesting point with this post but it's a very long discussion to take. I don't know any professional artist that doesn't use any kind of reference. Maybe they're selfish, but no one ever has shared or even mentioned what they use, maybe it should change, I don't know.
For example, I've seen the creator of Jojo's bizarre adventure making an illustration on youtube, he kept going back and forward with books of sculptures and fashion magazines as inspiration for designs and poses for the characters, he made an entire story and character development but copied poses for that illustration, is he stealing?

I remember seeing artists who posted daily copying almost everything of a painting I made to keep coming up with art, and of course, he/she didn't mention me, I considered it as inspiration, not necessarily a steal.

It's different when you copy 1:1 other's work. It shouldn't be considered art, just a study, or practice, and mentioning the original artist should be mandatory. Analyzing it further, if it should be monetized, sold or however they think to use it, that's beyond me.