They don't have to be leather. I wear Richa Evo summer motorcycle gloves, they're overly armoured on the knuckles but have armour all the way down the fingers.
But last week I got shot in the side of the knuckle, where it isn't armoured and oh my, did the air turn blue. My Richa gloves were around £50-60 new, you could spent the same amount of a top tier pair of airsoft gloves. I guess fingerless is just personal preference. I wear a medium glove even though it's difficult to put on buty they hug my hands great, meaning I'm not fumbling due to baggy fingertips.