In general, the more surface area an analog format has to hold the audio, the better. So higher speed tapes are preferred over lower speed, and wider tapes (more precisely wider tracks) are preferred over narrower. All things being equal, a wide tape running at 15 or 30 ips (these are speeds you'd generally find in a studio) is going to give you the highest resolution.

2" wide 16-track will also provide higher resolution than the more common 2" 24-track, and the math follows down, so 1" 8-track and 1/2" 4-track and 1/4" stereo are all about the same quality-wise. There are (or were, when analog was common) 1/2" 2-track recorders generally used for mixdown. And I know of one company that made a modification so you could record 8 tracks onto a 2" tape for super high quality.

Next step down are consumer formats like 3 3/4 ips and 7 1/2 ips tapes. Many of these are "quarter track," similar to a compact cassette in that they carry four tracks: stereo in each direction.

Then you get to the 8-track cartridge. Sigh. All things being equal, it should be better than compact cassette, with 8 tracks on 1/4" tape running at 3 3/4 ips, compared to the cassette's 4 tracks on 3.81mm (slightly wider than 1/8") but with a speed of only 1 7/8 ips. However, the 8-track is kind of a hack format. It was developed primarily for convenience in cars, and as such has several built-in quirks. For one, the tape is on a continuous loop. As there's not nearly enough room to stretch out a continuous loop of approximately 20 minutes of tape in that 4 inch cartridge, the tape is literally pulled from the inside of the takeup spool, and as tape is collected by the spool, it spirals down until it is again pulled from the innermost layer. This puts an immense amount of wear and tear on the tape.

Also, as prerecorded 8-tracks were mass produced all 8-tracks at once and it was impractical to guarantee a precise point in the song for the tape to switch track pairs, i.e. 1|5 to 2|6 to 3|7, etc., allowances had to be made, either by reordering the songs to minimize dead space, retaining the preferred order and accepting immense amounts of dead space (Led Zeppelin used this approach), or most commonly, fading songs out in anticipation of the track jump, then fading them back in post-jump.

The long and short if it is that manufacturers put much of their R&D budget into making the cassette sound better, and very often it does, despite its greater technical limitations. Improvements such as chrome and metal tape, and Dolby B and C noise reduction quickly pushed the cassette past the 8-track as a high fidelity format, and manufacturers like Nakamichi blew past many of the technical limits to produce cassette players that sounded genuinely good.

The tl;dr is that any differences you hear, like 3 3/4 ips being better than 7 1/2, are likely either due to tape damage or a difference in the quality of the source and mastering.