If the listener is relatively further away from the orchestra than the orchestra members are to each other, it mostly all balances out, especially when you add the room and bandshell reverberation (which tends to wash the note onsets to some degree).

This is also helped by the instruments in the back of the orchestra favoring the low frequencies, where the listener has less access to precise timing information.

As a (former) bass player, you need to start a bit early, yeah. But that's not so much for distance but because it takes longer for the sound to start. Pipe organ is of course much worse. I would do one concert a year sitting next to an organist... The keyboard noises and motion from him playing way before me were pretty distracting. And when we stopped during rehersal, he'd stop on the keys right away, but the organ would keep going for a bit.

Yeah, I noticed that when I started playing upright bass, compared to the bass guitar the sound starts with a noticeable delay.