A direct comparison between the length of the paths would be misleading: the LP encoding is analog (the width of the groove corresponding directly to the wave amplitude), CD encoding is digital (a single sampled value is serialized as a stream of 1/0 bits along the track, and is stored redundantly for error correction.) Despite the much longer total length traversed, audiophiles generally assert that CDs are more "lossy" than LPs - the audio information contained is less, in a sense. (Actually, I suspect that there is sufficient storage space to do a superior job, but when the standards were adopted, we didn't yet have processors fast enough to handle good compression or smoothing algorithms.)

A higher sampling speed (e.g., 48x) doesn't necessarily mean the disk spins that proportionately faster than a 1x disk, since the drive can simply sample from multiple tracks simultaneously.

A much lower spin speed is needed for audio playback than most drives are capable of. Consider: when duplicating a CD, the entire contents of the CD can be read in just a couple minutes with a 48x or 52x drive. More important is for the drive speed to remain relatively constant during playback. Due to inertia, this requires far less energy and causes less mechanical stress than continually varying the spin speed, even if the drive ends up reading nothing a good part of the time.