No, all of those had quiver slots which would use your special arrows in those slots just like they would use normal arrows you put in those slots and apply all relevant bonuses, like sneak attack and what else, using your normal attack.
Yep, exactly. All the Infinity Engine / NWN games (and ToEE too) gave you designated quiver slots where you put whatever missiles you want to use with your ranged attacks, rather than make their use a separate move in combat. You could, say, have Manyshot active and use it to spam elemental arrows, which were available in bulk and served as a source of extra damage first and foremost.
In the D:OS (and, by extension, BG3) games elemental arrows are mostly used as a tactical tool rather than a direct boost to your combat potential. Their main use in BG3, apart from the few special ones (thunder, Ilmater), is to create surfaces, because their additional damage is too low / infrequently triggered for how few of them are available for it to be in any way noticeable. While the traditional +x missiles don't seem to exist at all (yet?), so ammunition management isn't really a mechanic in the same way it was always implemented. I am not saying the game should just drown the player in magic ammunition instead of how it's implemented now, but given how crafting would be a thing in the full game, there would definitely be a bigger stock of non-regular ammo available for use, and to be unable to use it with extra attacks, sneak attacks, and maneuvers will be just incorrect from the rules' standpoint.
