When compared to other Enterprise classes such as the Constitution, Excelsior, and Galaxy, we’ve seen a surprisingly small number of Ambassador class ships, both in terms of unique vessels and on-screen appearances. What might account for the relative dearth of these ships?
For details, see: https://memory-alpha.fandom.com/wiki/Ambassador_class
The Enterprise C was this class:
That was the Enterprise right before TNG series.
My guess, similar to warship building enhancements during WW1, which saw massive innovations/enhancements in very short order, bigger and better ships (Galaxy class) were developed in short order, and Ambassador classes weren’t needed anymore.
Definitely a great design for something that was used more or less as a one-off.
A part of me really wants to reinstall STO to go fly mine around.