To put it simply, the whole track means that all the songs on the entire CD are combined into one "large" file (CUE is generally required for indexing when playing); the split track means that each song is a separate file.

It’s just a different form, it has nothing to do with the sound quality.

As for the fact that many people like the whole track, it is related to the proliferation of fake lossless videos on the Internet. The music files of the whole track have a LOG file when ripping the track, which can be used as proof of true lossless.