The ancient ruins filled with wildflowers, then the camera panning to Aya is a such a mysterious and calming opening scene. Her glittery costume looks like the Suzaku priestess dress worn by Miaka (夕城 美朱) from Fushigi Yuugi. Aya looks like a celestial princess and eternal fairy. =)
These older videos were not recorded in 4k. To solve this problem, dedicated fans use AI software to upscale old videos in 4K UHD. This is an expensive hobby for dedicated fans because you need powerful graphics cards and semi-professional knowledge of video technology to upscale independently. For example, I follow jpopization for their fanmade AI upscale MV in 2160p quality. You can leave a comment in their videos to request for an AI upscale, but there's a long waiting list because it also takes a long time to render these videos. =)