[Rupert]

If combat is common enough, and high enough stakes, then yes a high combat skill is very worthwhile. Even if the GM doesn't usually apply many environmental penalties (like those for poor light), high skill is useful.

In melee it lets you aim for harder to hit locations and still have a 16- to hit (for 'crit fishing'), and any surplus can be applied to Deceptive Attack, as that retains value until you've put enough in to reduce the opponent's defence down to 4-.

For a ranged attacker it lets you not bother with aiming, aim for small hit locations at great range, and hit many times with automatic weapons. With sufficient skill you can do things like hit the eye many times with an automatic weapon without aiming at short range, or at a longer range if you aim.

Many (but not all) of the benefits of high skill can be replicated by other, cheaper, advantages, such as Night Vision to remove lighting penalties, Gunslinger to increase hit chances, and so on. But high skill levels are flexible - in one fight they might be used to compensate for poor light, in another to deceive someone with high defences and hit them regardless, and so on.