it’s the circle of life!
music has to keep moving, pop feeds off the underground, the underground keeps moving.
I think everyone is robbing everyone at the end of the day, inspiration is only stealing badly.
ymmv.
But Max Martin is not trying to push the envelope, he is trying to make songs millions of people sing along to. Is that morally bad in some way? Or is it just a different facet of music?
The existence and ubiquity of pop music doesn’t stop you being able to enjoy whatever esoteric music you want to enjoy.
If you want cutting edge music to sell millions you’ll be waiting a long time - by it’s nature it will take time for people to understand and by the time they do, it will be pop music!