TLDR: If conventional frigates are "junk", then you need to move your measuring stick.
Simply put, no.
* * *
What do we have for frigates?
Hound, Cerberus? Shieldless and hard countered by some ships in a fight, but early-game pirates frequently do not have those hard counters. Okay as frigate-sized haulers.
Kite? Fragile rocket ship. Alright in early game, but not for long.
Warfarer? Frigate-sized Mule or Apogee (in terms of role). Good hauler, but does not have the stats to fight effectively past Galatia for long. Shepherd is better for a fight, and Cerebus is better at escaping a pursuit.
Shepherd? Nice support ship that doubles as a hauler. Basically frigate-sized carrier.
Lasher? Early game, the good weapons are rare or unavailable, so it is a melee-range LMG boat, which is effective until it starts fighting big things that outrange and outgun it, or bigger fights that take more time to decide than reduced peak performance from Safety Override. Later, it could get rare weapons that let it fight conventionally, but by then you really do not want to risk losing those rare weapons by mounting them on something relatively fragile instead of a bigger and better ship that needs those rare weapons just as badly.
Brawler? No defenses whatsoever. It cannot handle things by itself.
Vigilance? Missile ship that does not brawl as well as others.
Monitor? Damage sponge. Good as meat shield, but not as an attacker.
Centurion? Monitor-lite.
Wolf? Good beam boat, decent if not great attacker, has an escape button.
Tempest? Good attacker and defenses, and great speed. Main weakness is poor shot range. Drone can sometimes mitigate that.
Omen? Appears to be support ship at best, useless at worst.
Scarab? Weird attacker that can be effective despite terrible shot range, but costs a bit much to use.
Hyperion/Shade/Afflictor: Killer playerships, cowardly and possibly ineffective AI wingman (for deployment cost).
Combat ships of bigger sizes generally do not have a pile of mediocrity with blatant weaknesses. Most ships bigger than frigates are like Wolf or Tempest scaled up. Frigates in general are like Mules, Gemini, Condor, Venture, or various second-rate ships scaled down.