If more details, more accurate colors, and a digital file were enough to consider a work better, then all of the best art would be photographs taken by high-quality cameras. Fidelity can assist in art, but it is not art in and of itself, and increasing fidelity does not necessarily increase the quality of the art (even if it’s done by the original artist).

Remasters are a special case where fidelity is generally considered to be a straight upgrade. Generally, the master holds a relatively accurate representation of the artist’s original vision, but the copies may well be compromised due to limitations (usually technological). If you can overcome those limitations, then you generally should; while e.g. a piece of music on an 8-track cassette is better than nothing, precious few people would actually prefer it to a CD, high-bitrate MP3, or FLAC (or even a compact cassette). Similarly, video games are generally compromised due to system limitations, and games like Star Wars: Dark Forces Remastered really feel like what the creators were trying to make but had to downgrade to get it to actually run on people’s computers.