I found trap-spotting not to be a huge issue since it's a team effort, but rogues have enough starting skills that between it and their background skills, they should be able to cover the essentials without too much trouble. And while it's true that Charisma doesn't have an immediate combat benefit, there are plenty of charisma-based skill checks that let you bypass combats or gain better rewards. It's honestly not very hard to prioritize Dexterity and Charisma and still have enough points left to be decent at Wisdom and Intelligence. You don't need 20s in both after all!
My bard/rogue only had 14 Charisma, but between expertise, Friends and Guidance I usually only had to burn inspiration on the few endgame DC 30 checks.
