except you can only do it on one of your attacks on each turn.
Yes, and if you have access to different types of attacks, and miss with one of them, you get to use it on the other should you hit with it.
Sneak Attack is the defining ability that makes the rogue class what it is. Because of this, when designing a video game, you DON'T want to make it into a passive, invisible mechanic that you have to consciously think about to remember it exists. That's just following basic game design.
I'm usually very much in favor for sticking closer to D&D rules, but in this case I can't fault Larian for doing it this way. It's a core facet of how this studio implements D&D abilities in video game form. The battlemaster selects their maneuvers as special attacks, the rogue selects their sneak attack the same way. In complex games like this, being consistent is good.
The way they are implementing it now is a nerf to it. I also think, "invisible" is pushing it, especially since this game is still being developed. When it does damage against the enemy, they could separate the damage and make sure the player is aware that nice big number they see is Sneak Attack damage. If an unfamiliar player wants to investigate, off to the Character sheet they go. Of course that's just one suggestion, and I'm sure Larian could come up with something better.
