Counter point. I'm pretty sure people would rather have a smaller number of ships that can actually serve exploring the frontier than a bunch of cheap ships that might not even make it back with what they've found. Thus making them a massive waste of time and resources and much worse a waste of Starfleet personnel they will probably die when the ship doesn't make it back.
There is a very good that pretty much any explorer ship we see Starfleet build in Star Trek could probably qualify as a capital ship.
The frontier in Star Trek is extremely dangerous. I would rather spend more on fewer ships and actually get something out of them instead of building a bunch of canon fodder ships.
If a ship this large and powerful is "cannon fodder" because...
checks notes
It flies 0.2 Warp slower...
your entire fleet is "cannon fodder," we should surrender and all hail our benevolent alien overlords.