@Phenrir Ah, you're right that I was mostly considering Astral and Drover. Heron is in fact pretty on average cost-wise. Worth noting in that case however that the Eradicator (P) and Grendel are also cheaper than it. I think the Eradicator and Falcon in particular are important cases here because they can boast long range and good speed, both are generally excellent at punching down (which is the role the Heron is playing in this case). Their long range and decent defenses also mean they can stay out of the way of a firing ship and are not a complete liability if caught out. They can actually benefit from most, if not all officer skills. And with the Falcon, you can even slap Converted Hangar on there and still get a fighter bay anyway!
Also worth noting that it is directly competing DP-wise with the likes of Eagle, Apogee, Fury, and Gryphon. The second-to-lattermost being another excellent punch-down style ship and the lattermost of course being the quintessential "fire over allies, from long range, at any target, and still do good damage" ship. Though obviously that is an outlier

I would also say that carriers do actually have that problem with losing a lot of value, because once the enemies on the flanks have been peeled off, (generally) all that is left is the enemy blob, and the enemy blob has overlapping PD grids that absolutely delete fighters on the approach. This alone lowers their effectiveness massively (fighters are just minor distractions) but the replacement rate goes down as well, which can be an issue.
However, take all of this with a pinch of salt. I have seen fighters used effectively. BigBrainEnergy put out a "midline cruiser doctrine" type fleet showcase and it had effective fighters, so I am not saying they are totally useless (I'd rather them than Hounds or Kites!). I have also not done a lot of personal playtesting with fighters, and I intend to do so on an upcoming playthrough. So really most of this is based off of general gameplay observations ("vibes"), which as Vanshilar will note can be biased or misleading! (just ask him about SO fleets :p)