Many of the wind band instruments have increased in size (over the past 60 years) too much (in my view).
In addition to the fact that there are too many alto and high-tenor voiced instruments in wind bands already, the 21st century wind band sonority is too "mezzo" and blurred - unless it's some sort of absolutely top-level band (whereby the amount of energy produced allows the symphonic/orchestral (extra-large) instruments to resonate as they are actually designed to do so.
Clarinet students (due to their private/studio instruction advice) are using mouthpieces that offer a very mellow type of resonance (again, unless pushed to their top sound production potential). Those are supposed to take the place of the violins, yet (unlike violin resonance) there's no shimmer in modern-day clarinet sections.
Bell-front (American "crossover") baritone horns - smaller than most British-style euphoniums (other than YEP-201 and clones), yet larger than British and continental European "baritones" - offer more high overtones compared to British-style euphoniums and - with the bell-front design - more of those overtones are heard, rather than lost in the shell or clouds of an auditorium.
Then, these "almost bass" large-bore tenor trombones, played with near-euphonium-size mouthpieces, no less...
These are the instruments used in symphony orchestras, so they must be better.
Millennials and younger have no idea about that to which I refer, because they've never experienced it.
Technically, even my oldest daughter isn't even (quite) young enough to be classified as a "millennial".
getting off-topic, so IGNORE THIS:
proposed law:
Local, state, and federal (when subsidizing local schools, which is always) government shall only supply 3-valve brass instruments (compensating 3-valve are allowed), non-F-attachment trombones, bass clarinets limited with range only to low E-flat, and single F or single B-flat horns to school systems, along with entry-level percussion instruments. (Baritone saxophones with range to low concert C are allowed, due to those being the only type made.) Anything with higher-grade features must be donated by individuals, for-profits, and non-profits, or furnished by the parents of individual students.
proposed marching contest rule:
No electronics (neither AC nor DC voltage), no stringed instruments, and no props (stand-alone unmanned visual effects which are not deemed to be musical instruments) are allowed on the field nor in stadium or field area. Moreover, nothing that isn't continuously carried and operated by one person (who must not remain stationary) is allowed on or adjacent to the field.