I agree. This retro vibe that discards mid and late 24th century designs does annoy me.
I had a headcanon theory that fits this.
I had the idea that different shipyards had different design aesthetics and different engineering optimisations and tradeoffs, which would wax and wane and become dominant at different times. For example – the San Francisco and Beta Antares Fleet Yards favoured long, sleek, lean, elongated designs, like the
Constitution,
Excelsior, and
Sovereign. The Utopia Planitia and 40 Eridani A Fleet Yards favoured these rounded, smooth shapes, like the
Galaxy and the
Nebula and all those background 24th century ships we glimpse –
Cheyenne,
New Orleans,
Springfield etc. Ignoring multi-vector assault mode for a moment, the
Intrepid and the
Prometheus are basically sister ship classes on paper, but the
Intrepid is the cuddly chonker Utopia Planitia/40 Eridani A version, and the
Prometheus is the stretched-out skinny San Francisco/Beta Antares version.
For a long time during the decades of relative peace in the middle of the the 24th century the Utopia Planitia design language came to dominate with these elliptical saucers and bulbous nacelles, though it was ultimately discovered that while this method gave ships a much larger volume for a given mass and worked well for self-sufficient exploration vessels in peacetime, it was inefficient for more militaristic ships optimised for battle conditions. Then with the destruction of Utopia Planitia the manufacturing capacity for that type of design language was effectively lost. This is what we're seeing in PIC – leaner, more angular ships, that are fast and well-armed but much less "friendlier" in design and less comfortable than the best Utopia Planitia had to offer.
Also, I entirely agree that the Dominion War fleets should have had these types of ships rather than endless
Excelsiors and
Mirandas. But the lack of
Ambassadors or
Cheyennes really was an oversight, especially with the advent of CGI and when we start getting to the frankenfleet vessels.