To a certain point, you can raise/lower your action just by neck straighness alone (bearing in mind we are talking a few thousandths of an inch, which you CAN feel).
Of course, as well there is no accounting for how one neck that's fine for you may feel to someone else, as it's very subjective.
Typically, when things begin to fall in line (correct neck relief, proper heights at the nut and 24th fret, and your bridge height, all these factors total up), the action will be lower without the bridge height adjustments running out of travel, even though it may look very close.
Lots of us have had in our time a bass that was just fine just as it came out of the box, was stable enough that it never really needed adjusting to suit us, and it never got touched. Eventually, they will need some fine tuning, whether we do it ourselves or take it to someone qualified to work on it.
However, any experienced player would know that a bass that was a little high-actioned for our taste but with no obvious wood or hardware issues could easily be adjusted to suit, so I think that for whatever reason, this 'buyer' decided to look for the OUT door . . . .
J o e y