Fighters are hopelessly outgunned, and most are slow. They cannot be relied on to kill stuff, unless numerous wings are deployed. But I do not use a carrier fleet.
My endgame fleet looks something like the following: Paragon, Dominator, Eagle, Medusa x2, Hyperion, Shade, Tempest x4, Lasher, Atlas x3, Ox x3. Eighteen ships minimum. The rest get filled quickly by boarding opportunities after most battles (because boarding is cheaper than buying from shops, if you know what to do). I have no room for fighters. This fleet is designed to go into totally hostile systems (with no non-hostile bases available to stash loot and/or buy supplies) - with transponder off to attract as many enemy patrols and detachments as possible, chain-battle all hostiles, and loot and board as much as possible. With the small bounty from a commission, this activity is very profitable thanks to number of enemy ships destroyed.
I do not need fighters to kill things. Paragon can kill everything thrown at it single-handedly. Hyperion can solo fleets numbering up to thirty ships. Cruisers and Medusa get sent to kill smaller fleets that do not need Paragon or Hyperion. The main problem is killing Timids or carriers that are faster than my Paragon or cruisers, and they will happily kite my ship if I am dumb enough to chase them. They want my point? They will need to fight for it! But they will not, and thus, stalemate until one runs out of CR, which is always them, and not me. Thus, I win... after waiting about five to ten minutes.
One among Paragon, cruisers, Medusa, and Hyperion is sent to solo fleets. The frigates are sent to mop up pursuit. The Atlas haul the big piles of loot generously dropped by gigantic detachments, and the tugs are needed to keep my burn speed up.