That's the point, one character is literally not supposed to be able to cover all the bases. So you play again and see new stuff. I have a lot of issues with this game (companions engaging in dialogue instead of the main character was a big one in fact) but I think that making it so players have to deal with not being able to pick everything is a perfectly fine choice, creatively.
At the risk of repeating myself, my point is that your Tav is just one member of a team of people who have different backgrounds and diverse skills, and Larian is telling us that we can't tap into that skill diversity (aside from passive checks). In a tabletop game, we definitely would be doing so; why can't we aim for that here?
