>>96138
Part of it is just how oversaturated the style has become. I remember going to the gas station a while back and seeing some kind of drink can with artwork similar to what synthwave acts are using.
The music might be a higher priority, but imagery is still important in how you perceive the music. Imagine a hissy old four-track black metal release with colorful Boris Vallejo artwork instead of homemade monochrome artwork or high-contrast black and white photos. It wouldn't fit the feeling of the music at all.
That's not the case here, though. I'm just getting bored with the usual look.