We don´t need the nuts all the time to win, especially not when we act last. Many of the nut hands are unlikely from what we now our opponent can have.
Making a straight with high cards is equally likely as with low cards. It is more important to see how connected the hand is and where the gaps are to see how many nut straight that are possible.
Your missing some important aspects.
1. We want to make the nuts so that we get paid. If the board is 4698Q for example it's hard to put a value bet in despite flopping a super strong hand. Likewise we pay off other players who have us beat at this point.
2. We need worse hands to pay us off. If we do have the nuts, say the flop is 764, can we expect someone to be playing 35xx and the board has to blank out pretty spectacularily to still have the nuts on the river. With KQ on a QJT flop it's a lot easier to have the nuts by the river.
3. Hitting 2 pair is quite bad for us, we have a lot of reverse implied odds with this, where we're paying off a higher 2 pair and people with sets a lot. At least with hands like AK when we hit 2 pair, we can dog a full house to suck out on a lower set.
Over all playing hands like this gets us into trouble as much as it's good for us being on the button. Now make your hand double suited and it's a whole different story, i'm just not a fan at all of what is in all intents and purposes an unsuited hand.