This.
Not trying to be rude, but IMO this entire premise is crap. I'm going to explain why I think it's crap, and when I'm finished telling this story, you'll at least understand why I think it's crap.
About 7 years ago, I went to a
TB GTG in Seattle. Anyone who's never been to one, you owe it to yourselves to go the next time there is one in your area. It's show & tell for bass players. Imagine the fun of seeing other players' special basses & amps & cabs & other unique toys, and imagine the joyous cacophony of 3-10 bass players playing at the same time (not together) -- and not just playing, but testing their chops, checking out other people's basses and amps.
I brought the bass in my avatar, a Warmoth 3-pickup Jazz. I also brought my rig, then a TC Electronics amp into a
Phil Jones B6 cabinet. I also brought my guitar player friend. We had beers and socialized, but while I was geeking out on all the gear, he sat down and observed.
What he observed is relevant here.
As you can imagine, multiple bass players playing simultaneously in an uncoordinated fashion is going to result in a lot of sonic mud. But as my friend watched, he thought he could distinguish the sound of my bass and amp being played from out of that mud. And as he watched the fingers of the guy playing my bass, sure enough, that's what he was hearing. Fairly clearly, in fact. At the time, my friend thought that it might be the guy's technique, but as he watched, the guy put my bass down, and then picked up someone else's bass, and then everything the guy was playing got lost in the mud. Then someone else picked up my bass, and then my friend could hear it again, verified by watching that guy's fingers as he played. And as he observed, he also watched other people play other basses through other amps, and try to listen for distinct lines being played, and most of the time he was unable to hear any.
At the time, I didn't know any of this was happening. He told me about it later, on the way home.
So why would a guitar player be able to hear my bass among all the other basses? In my opinion, the difference was the Phil Jones cab. The amp wasn't that special. The bass played a part, as it has a broader tonal palette than most basses, but the real difference between my rig and anyone else's there was the 5" drivers in the PJ cab. If you've never heard a Phil Jones cab, you'll be stunned by the amount of bass those 5" drivers can produce. Phil Jones cabinets articulate better than pretty much anything else IME & IMO, and the key is those 5" drivers. Six of them in my cab represent the same surface area as one and a half 10" speakers, but with more and tighter control than a 10" driver would have.
So if my bass can be heard and not be buried by other basses being played at the same time, it's sure as hell not going to be buried by a kick drum & snare drum. (IMO, a P bass runs the most risk of being buried in a mix because there is just less you can do with it, adjustments-wise.) It's also why I don't worry about boosting mids to be heard in the mix. I believe my sound can be flat or scooped and be heard well enough, if the sound is being faithfully reproduced with enough articulation. I know that puts me in a very small minority here on TalkBass, but I feel like I have good reasons for thinking the way I do.