Yeah, the fighters in Elite Dangerous are always pretty limited to their maximum power output.
But you can tweak it a bit by disabling things like Cargo Hatch and Frame Shift Drive during combat.
But on the other hand, a Eagle or a Viper isn't build to compare with an Anaconda or even a Python.
At least not alone. Maybe in a swarm (wings).
The downside is that later if you got enough credits you tend to fly rather a Vulture then a Viper.
Because it can nail a RES Anaconda alone in no time and so make credits faster.
But i has one in my Arsenal of Ships like a Sports Car next to a Family Van, to ride it once and a while.
I spend a bit of Money in the Skins, and i want to use them.
After finally noticing a ship sell loses me every time 10% of its value, i'm now in on the Pokemon approach: Gotta catch em all!

This way it takes longer to get a Python or an Anaconda but i have a well outfitted ship for every task now.
But back on the Viper. It is not this expensive after all, and so it's limits are somewhat explainable.
And i think in Elite Dangerous it always has something to do with the size of the ships and so the size of the heat radiation on it
what power output it can handle. I think it is not only game balancing but a bit of a simulation aspect on it.