I’m a bit confused about why they put on Starfleet uniforms (whose design I don’t particularly like), but perhaps it will become clear next week.
Starfleet should really stop being cheap in building commbadges.
Gave it a 9.
One of the reasons the kids may have put on the SF uniforms was to officially/openly declare their defiance against the Diviner.
They DID concot a plan to rescue the Tars Lamora slave population after all.
Also, the recent Time anomaly stunt from last week gave them a different perspective. They have worked together (albeit separately) across timelines to save themselves and Janeway's mentoring may have also had something to do with it.
As for the commbadges... to be fair, on ST: VOY, they DID survive a planetary explosion and emitted a locator signal (which was how SF tracks the victims).
One would have thought if the commbadges survived that, it would be extremely difficult to just step on them and crush them... though there may be a difference between an explosion and active crushing with something metallic and heavy (but if you ask me, this really shouldn't have played a part at all).
Designing stuff from superior synthetic materials which would prevent the badges from breaking by simply stepping on them would be doable.
Even today we can design phones and laptops that can be dropped from a very high ground and survive unscathed (on the screen or functionality)... phones can be made water proof too.
Its just that most commercial products aren't really designed like this. Also the term 'military grade' is just a fancy way of saying 'designed for the most part properly from the get go'. Manufacturers of conusmer goods don't particularly care about stuff like that ... so if they make a phone or a screen break proof or water proof... it just gives them an excuse to slap a higher price on it (despite the fact it wouldn't really cost them more to do it properly from the get go).
Starfleet and UFP are in the future... and given the society they built, sustainability, efficiency and making stuff that LASTS (and is pretty much difficult to destroy by hand or foot - unless you vaporize it) would be a given.
It actually would have been funny if the Diviner stepped on it, only to learn nothing happened. Then trying his best to jump up and down on it in an attempt to break it, untill finally he draws out a phaser and vaporizes it (which would technically be the only viable thing that could do the job).
However, the Diviner was in a pretty tough metallic (although easy to move around in and use) armor. Its possible those metals would have a directly opposing force which could break SF badges when you step on the,
Similar to Georgiou breaking one with her boots... it seems more like a thing she would have some alloys in her boots which would allow her to break the badge casing.
At any rate, its already possible for us to make stuff that doesn't really break... SF would have definitely gone down that route, especially if they use badges to track victims of accidents, etc.
It seems more like the case of real world people not understanding that stuff can be designed that doesn't break easily and will in fact last (and can be easily repaired and maintained... or designed to NOT need repairs or maintenance almost never... or that it can be designed to be self maintained - this is something not fully explored in Trek if you ask me).
But I guess it was for dramatic purposes too (but it would be nice to learn it wasn't a real commbadge).