EMG's don't have a ton of low-end at all or particularly airy highs. They're just a focused punch in the upper mids. So they're some of the tightest pickups around. Objectically and measurably tighter than ANY passive, IME. Don't get me wrong, I think good passives have their place as well, but they just don't do the tight, focused (that sometimes people feel is sterile) thing as well.
I used to love EMG's. I tried every different one from the classic non-X range I could get my hands on (not really ALL of them, but the 81, 85, 60, 89, 81TW, 57, 66, and Hets). I even tried a couple of the X series and the Jim Root set. I started playing EMG's maybe like 20 years ago at most, but I always thought they sounded consistent...
... Until a couple of years ago. I got an 85 and a 57/66 set. They all sounded horrible.
I started doing some research, and apparently, one IC that they used on the preamp was discontinued on 2018. So I sourced an older 2017 set of the 57/66 set, and night and day difference.
Nowadays, I find Fishmans do the EMG thing better than EMG's. Especially since they've got a few slight tweaks on the Modern Ceramic recipee, which I find is comparable to the EMG 81, just tighter even and clearer.
Also, couple of interesting EMG facts I've found throughout my experience with them that you don't usually read about. I don't find the 81 all that hot. A really hot passive like an X2N, 500T, or Black Winter easily overpowers it. Also, the 85 is actually hotter than the 81. So is the 57. And the Het Bridge is by far the hottest.
Techincally, they are all the same output because the preamp running at 9V limits what they can put out. But some of them are louder before they hit the preamp, so the preamp clips and distorts more, making them feel hotter than they actually are.
So yes, I guess you could call EMG's "compressed" in a sense. But I think the right term would be "clipped". They distort a little internally when you strum hard. At least they do at 9V. So it's almost like they've got they're own little subtle overdrive/boost circuit built in that activates when you strum hard.