And in the Dominion War, when the Federation was fighting for it's life, anyone remember Starfleet using any Intrepid class starships in battle?
That says something.
But how long does it take to build a starship? The Intrepid class entered service in 2370, with the Dominion war taking place from 2373.
By 2373 we know of there being 3 ships? The Intrepid, Voyager and the Bellerophon, I think Voyager and The Bellerophon were commissioned in 2371. So with Voyager being away, that leaves 2 Intrepid class ships that are known about at the time of the dominion war. Surely it would be much easier and quicker to upgrade the countless excelsior and miranda class ships than to build more new ships?