I’d be inclined to agree with you if there wasn’t such a specific divide between the flavour text and the content. For instance, the sharpshooter feat doesn’t specifically let you make shots that others think are impossible- saying “I use my sharpshooter feat to shoot the BBEG in his castle three hundred miles away” would certainly be a shot that others think are impossible, but I doubt any table would let that fly. Saying “I have the crusher feat, so I’m going to break the enemy’s bones to debuff them” would fit directly into the flavour of “You are practiced in the art of crushing your enemies”, but it’s also not what the feat does. For the halflings, you can take the bountiful luck feat, and then use it, despite the flavour text clearly stating “You’re not sure how you do it; you just wish it, and it happens”- thus precluding anyone who knows about the feat or what it does from taking it. Lucky: “You have inexplicable luck that seems to kick in at just the right moment.”, but it’s actually very explicable, follows predictable rules and doesn’t kick in at just the right moment unless the player knows just the right moment to use it.
Yeah, there’s a heck of a lot of overlap between Traveller and 40k- they were developed around the same times (classic traveller was '77, Megatraveller was '86, Rogue Trader was '87 and then Traveller: The New Era was '92) so there’s a lot of cross-pollination between the two