Again, I'll point to China as a counter example. People there don't see technology as magic, even though Chinese tech is just as complex.
I aslo don't really agree that the tech in the golden age of sci-fi was simple. Take something like the Apollo program. Sure, people can understand the concept of a big rocket, but the details of how the whole thing works is beyond the ability of any one mind to comprehend.
I think the trend towards magic in the west is simply escapism. Most people don't want to engage with the world that's falling apart around them, and to contemplate the likely futures which are looking imcreasingly grim. So fantasy worlds that are divorced from lived reality become increasingly increasingly appealing.