I'm not surprised. The issue is the recording medium. Yes, vinyl isn't as good as tape in terms of noisefloor and distortion, but it preserves much better much more easily. My layman's amateur mastering engineer understanding of it is that, when CD first came around, and you got some of the earlier re-releases of work recorded in the 60s and 70s released in the 90s or so, we had the benefit of having much better tape machines to read the tape with than we had to record with. So, we could genuinely pull more detail off the tape with less noise just because the machines were better and the tape had aged reasonably well. Fast forward another 20-30 years, the tape is really starting to show its age, but we can also do a lot more DSP in the studio now to remove a lot of the noise and other artifacts of tape Not really going to claw back any dynamic range that was lost, but we can definitely still make it listenable. If you were the Beatles. Or Led Zep. Or Pink Floyd.
But if some or all of those tapes are lost, or damaged beyond digital repair, or they were never maintained because the album didn't do well, or it never got distributed by a major label and the masters rotted in the drummer's basement for 30 years while he went on to become an accountant. Then, you're just schiit outta luck.
Some of these remasters are done with a modern audience in mind, so it needs to sound like a modern album for it to perform in the way the label hopes (because god knows they didn't get enough money out of it the first time around). Some are such a niche thing that they sound like straight digital transfers - Donovan jumps out as an example to me. I shifted the bit register of one of the tracks I like to give myself 6db of headroom to do my own little master, just to see what it would be like to work on something like that. And in 2 minutes I had something with a lower noisefloor, a more full sound, and almost no loss of dynamic range (after giving up 6 db of the existing recording to be able to mess around with it). And that was without something like Izotope RX to get rid of the noise, that was just some basic EQ.
Realistically, I think you want to land somewhere between straight transfer from tape and modern re-working. Some noise removal and a little digital EQ to shift the tone a little bit, tilt it slightly towards a more contemporary sound, is fair game in my book. I'm not intimately familiar with the original albums, but the Led Zepellin remasters seem fine to me. Definitely doesn't sound crushed or anything, but there are now some nice high-res options for those albums. The most recent Beatles remasters push things a little bit for my taste, some of the gating is a bit aggressive to me, but most people call those the definitive cuts.