From how they are talked about in Discovery, the Constitution-class is THE ship to be on in Starfleet. Even in Kirk's day, the Starship was still sort of a thing of awe, and a desirable position. Even the Commodores were defining careers by one's command of a Starship, and that being a rare thing. (and in those days "Starship" was basically a ship like USS Enterprise).
Alas, that's cherry-picking, because "starship" for anybody who believes in DSC also includes midgets like the
Franklin now.
We know
Constitution is hot in DSC. We don't know why, though. We can rule out size now, but not much else. Is she new (or recently refitted to be newer than new)? Is she old and venerable? Is she capable and well-working? Or such a dud that getting her moving is a challenge worthy of the best of the best? Does she have superior range, for those exciting deep space adventures? Superior guns? Superior numbers, so everybody gets to train aboard those (unlikely-sounding, given the gist of Burnham's prompting of Tilly)? Inferior numbers, so it's a rare privilege purely for the rarity value of it (unlikely again, because the registries just plain don't have room for ship classes markedly larger in numbers than the two dozen
Constitutions of which one dozen would survive to Kirk's days at the given attrition rate)?
The casualties in Kirk's years of this class seems to be unusual, and most are from rather superior creatures or machines that Enterprise herself only barely survived.
Curiously, we don't hear the casualties called unusual, in the respective episodes or elsewhere. And we don't hear superior creatures called unusual, either. Fighting those might be the bread and butter of starship work - and even slightly lesser ones would demolish non-hero ships anyway.
By the 2290s it is likely the class is getting tired, but not in the 2250s when they are the top game in the Fleet. Even to those on the most experimental starship in the fleet.
I guess the jury will return from recess on that soon enough. Is Pike flying the top of the game and now has to settle for a mere
Crossfield? This would be likely to be clarified in dialogue early on, really.
It's just that
Constitutions in DSC have done nothing yet. But, curiously enough, both Pike and April have done something to earn a place in a very exclusive list of decorated starship captains. Did those feats have anything to do with
Constitutions?
It is possible some Constitutions were still in service, but they were becoming more and more rare since production had stopped around the time full production of the Excelsior-class was underway.
On the other hand,
Constitutions are also absent from DSC S1. Absence might stem from deep space duties, with only fellow
Constitutions ever having a chance to meet these far-ranging ships. Or from combat duties, the
Constitutions being the true warships of Starfleet at the time and therefore reaping glory in locations maximally distant from Lorca's weak science ship AND from those UFP weak points where Lorca has to save the day exactly because Starfleet's warships are elsewhere. Or something else in that vein.
It is suggested that USS Republic was still in service as a training ship in the Sol System and hadn't left the system since the 2320s. The same ship Kirk served on as an ensign in the 2250s.
Or a completely different ship launched in 2318. Perhaps using a
Republic for training is tradition (even though we get no indication Kirk's
Republic would have been a dedicated training ship, especially as DSC hammers in the fact that cadets are everywhere, even aboard top secret research ships, and OTOH Kirk was no cadet when aboard the
Republic).
Timo Saloniemi