Thats actually pretty much *exactly* what it means. If you go to a store and they say "for $1 you can get a hotdog or a corndog", so you give them a dollar and grab both.... they are not going to be pleased.
There's a funny story about that, actually. It turns it, there's been at least one case of a country which abandoned its own currency in favor of the US Dollar, and while they were able to get enough cash into circulation to keep the whole system functioning, they suffered from a deficit of coinage. There were plenty of bills to go around, but not enough dimes or quarters. The result was that, for a wide range of low-end goods, just about
anything was going for exactly $1 - be it a loaf of bread, a dozen eggs, a CD, a paperback novel - that was the smallest denomination they had access to, so everything cheaper than that was just rounded up.
It's kind of a similar situation here. Our smallest increment of time, during a turn, is "you can manipulate an object up to a certain complexity as long as it isn't so complicated that you run out of time to swing a sword twice or cast a spell"; and that's a hugely variable chunk of time, but it does give some examples. Sheathing a sword and drawing a sword are both okay, as is retrieving a potion or opening a door, but operating one of those hand cranks to raise or lower a drawbridge is too far.
Other things are not on that list, so we have to use our judgment, but it's easy enough to make comparisons with what's already there. Does it take any more time to draw two swords simultaneously than it does to draw just one sword? I think it's obvious that it does
not, because we've all seen someone perform that action and the hands clearly move independently of each other. You might be able to make an argument to the contrary, and I can't imagine one that I would find compelling, but the DM is there if you can convince them.
Does it take any more time to sheathe a sword and subsequently draw a javelin than it does to just sheathe a sword or just draw a javelin? I think it's obvious that it
does, but it's not obvious if it's
enough to say that it would take your whole turn to do just that. If it takes one of your six seconds to sheathe your sword, then even if it would take one second to draw a javelin, that doesn't mean it would take two seconds to perform both actions; it might only take 1.4 seconds to do both, since your hand is already in the right area. Nor is it sufficient to say, even if it
did take two seconds to perform both, that this is beyond the time allotted by the Object Interaction and now it takes your whole action. I mean, the combined motion is still much closer to sheathing a sword
or drawing a javelin than it is to lowering a drawbridge.
I might agree with you if this was just a series of abstract logical statements that didn't correspond to any physical actions within the narrative, but everything in the game
means something, and the rules are just a best-fits reflection of that world after making a bunch of assumptions. There's a reason why we have a DM to arbitrate, instead of leaving it all up to a computer, and the fact that we have the DM to interpret the rules is a huge part of why those rules are what they are.