Rogues are great. Maybe you're not using Sneak Attack right. Astarion has saved the game more times than not. Spider fight, he would attack and dart back into hiding so Spider wouldn't know where he was. Hit, hide, and they dead.
And yrs, everyone can lockpick, but having proficiency still makes it so Astarion has the best chance of success. Later levels will also make Rogue better long term.
