>The only reason for keeping far away would be to have time to react to missile launches and attempt to intercept them. But that's not different than what ships do at sea.

Yes, that's why you would do it in space, too. The only reason sci-fi media doesn't do it is that it would look boring onscreen. You're just sitting there in the dark then all of a sudden a tungsten rod moving at some fraction of c vaporizes your hull, or a cloud of goo attaches to your hull and you bake to death slowly because you can't evaporate heat well enough. And of course actual lasers in a vaccuum are invisible.

Everything in space is so big, spaceships have to be so fast to get anywhere in a TV-friendly amount of time. I feel like spending an appreciable amount of time inside visual range would be like 2 enemy fighter jets pulling up next to each other so the pilots could sword fight. It really needs the deliberate cooperation of both parties. If anybody even breathes on their control stick they'll drop out of range instantaneously. Not that I'm complaining lol, I like to be able to see things in my TV shows.

Assuming identical weapons.

But if your weapons outrange your enemy you will want to keep the range long. And if your weapons suffer less range penalty than theirs do you will want to keep the range long. The flip side being that if you're on the other side of either of these scenarios you want to keep the range short. And that's before you consider the effects of shielding--most universes with shields make them more effective against weaker attacks. This would mean that if you're facing lighter weapons than your own you keep the range open, if you're facing heavier ones you close.

Hitting debris at these velocities would be instant death. Debris comes from other vehicles (generally). You’d never want to be going where other people are, for safety.