One of the downsides of a skill system is that mid to late game, you'll be carrying your beefed up skills to do task in new unexplored areas, which unless their base value is put extremely high, would be done in milliseconds. Where at the start you get couplers in 15 seconds, to make your initial interactions with future couplers, they would have to be multiple base minutes.
With Familiarity, similar actions in later parts of the game can still be similar in base time and not zip by.