As people have said, there is no "totally free" group with capital ships. Also, the point of Discovery is that there is no "endgame" as you put it. My BAF pilots have no intention of getting GBs, my trader is quite fine with a Shetland (granted, it's as large as a dunkirk, but it's only got one gun for crying out loud), my newb helper is happy with his rhino, and my pirate loves his "pretty" Barghest, which by the way was involved in the destruction of multiple capital ships, including a cap VIII Liberty carrier. Now then, I think I'll tell you a little story about a capital ship pilot who thought he could go anywhere:
Once upon a time, there was a corsair cruiser commander. Since it was a lovely evening, he decided to go to Leeds, to see the smog clouds. However, he went too close to the planet, where the BAF were having a tea party in their fighters. "No problem" said the cruiser commander, "my ship is too big and shiny for them to scratch!"
But the BAF didn't like the corsair being there, so they stopped their tea party, and all 8 of them went to give the corsair some tachyons as presents. The corsair's cruiser, despite being the shiniest cruiser in the corsair fleet, couldn't deal with all the tachyons and so, within a minute, it had exploded.
The end.
And the moral of the story is: Capital ships shouldn't mess with massed fighters, let alone bombers. Many factions have the might to bring up at least a couple of bombers at any time, and so your capital ship, as said before, will be very vulnerable. Feel free to take a look at your battleship's shield and compare it with a cruiser shield: 1000 more regen per second? That's less than an extra fighter's worth. 100,000 extra health? going to go down in less than a minute more. 4x the armour? Maybe you've got 5 minutes, 10 at the best before you're destroyed, and that's just from a fighter group. Bombers are much harder hitters.