I mean, if you're into realism: most space sims in general are really not ideal. Realism in FreeSpace would be a lot of other things too: you'd see gravity, you'd probably need some explanation for all pilots everywhere do not get fried by cosmic rays/radiation (which is all over the place in space and lethal to humans), how subspace ACTUALLY would work, and probably better explanations for all the weapons.
I like viewing it in a different way which is: 1) you're looking at a game and it's best to accept that most of what's been put together is for the experience and fun of it, not to really simulate how space as we know it is and 2) it can be seen as an alternate universe with different laws of physics than our own. For all we know, in this parallel reality of FreeSpace: gravity and space work entirely differently, and all ships in space experience friction with some invisible cosmic matter that limits their ability to move.
The larger a ship's mass, the more energy is required to move it in a non-linear relationship, which then explains why capital ships always move slower even though their engines are giant. The only problem with doing this is that you'd have to find some way to apply those rules to planets, and that's not easily done. Under the physics of FreeSpace, aerodynamics and the laws of electromagnetism as we know them in reality probably do not work at all the same way.
The extending problem with that is that would probably then mean that human life may not actually evolve in a universe with the physics of FreeSpace, unless of course we consider the possibility of infinite alternate universes, all of which may have differing laws of physics. But that's more philosophy and thought ooze than real science.
So, if you want realism: go work at NASA or something. Realism is often boring for a videogame (or awesome, depending on how it's done) and more difficult for developers to create with full accuracy. Consider that in reality: you wouldn't even be able to see the ships you're firing at because they're probably too far away. You wouldn't hear them either. If you flew too close to planets or stars you'd get sucked into them from their gravitational pull. That just sounds like a terrible videogame to me as a combat sim. I mean, that would be cool if it was more like a space exploration game and it had a totally different concept/genre to it but realistically space combat is not really a thing. Hopefully, actually, it won't be, or won't be for a super long time.
The reality of space travel is also supremely difficult and horribly dangerous with modern or even near future technology.
So, I'm completely happy with the WWII in space idea of FreeSpace, and you should be too.
