If were talking about a lone battleship (say like a kirk) walking into leeds, than ofc the battleship could get put down in several different ways. Bombers, a horder of fighters and ofc Gbs and other BS will kill it. But in terms of a group battle a BS has much more potential, since it has figthers/gbs/ dessies with it to cover it, it can deal stupid amounts of damage with anti-snub weapons and ofc heavy turrets like the heavy mortar and razor can insta kill gbs and in some cases even crusiers will get insta killed.
Unlike crusiers, BS rely more on the pilots skill. Loadouts do have a major effect on it, but its still possible to kill 3 bombers without a razor loadout vs with a razor loadout.
In terms of other capital ships? The BS is by far the one to be feared, there are tactics to use to take down crusiers quickly, most people just dont know of which gives off the impression to most new players that they cant do much against gbs and crusiers because "no CD" or "guns too slow".
GBs can also fall on the skill of the BS pilot, its very easy to insta kill a gb pilot without much experience.
I know im really sounding like an all talk no walk sorta person but it is possible.