One benefit of utilizing a favorable gear ratio mouthpiece (ie shallow as hell) is that you don't have to constantly worry about crossing the threshold into over training. The other is that you can spend more time online or with your girlfriend. Less need to practice if only to maintain adequate endurance.
For some reason it still seems popular to train students, both high school and college, on the deepest, sharpest mouthpieces possible. Thankfully this has changed a little since i was coming up. Back in my college days the prof had us all on Bach 1C or bigger. He himself used the Schilke 22. Played it well in fact but the man had thick fleshy lips. Yeah and he played some four hours a day minimum. Practice helps.
He didn't however have to do any big band lead playing. Plus like we old timers now he had long term skills to fall back upon. Back in college we were all developing. Our embouchures hardly more than weakly programmed jello.
That said I still keep a nice "bathtub" piece in my collection. It is well rounded though. In flugel horn shank to which a cornet to trumpet adapter works dandy when i want more over tones in the trumpet sound. Or more lower register accuracy/endurance for same.
But most the time I keep a shallow piece in my ax. By developing a technique where i rely on the metal more than my lip I almost never fall short of on endurance a gig. Plus during those inevitable times when gigs are few and my practice time limited i can still pull off a couple sets of big band lead chair parts. Even if the horn never left the case for the whole week before. True.
Despite the obvious problems with the idea most classical teachers still push larger pieces on their students. And for sure there are times when these "bathtubs" are needed. However it is easier to switch to a deeper piece when the need occurs than to the shallow end of the pool. Just the way it seems to me.