To add on to what the other commenters have already said - this is especially true for marching bands where you are even further spread out and your distance to various sections changes over the course of the performance. You have to learn to (at least somewhat) disregard what your ears are telling you and focus solely on the drum majors for staying in time. Listening to the drumline to keep yourself on beat can be a very bad idea when they're half a football field away.

This effect is amplified even more for enclosed stadiums where there tends to be a large amount of echo, and can really be quite disorienting the first time you experience it.

It's one reason that a conductor sends visual cues to the whole orchestra at the speed of light. That's the base clock source

one interesting thing is that you will fairly frequently see professional orchestras be out of phase with the conductor, but everything still works out.

Does a really good conductor train each section to come in on different parts of the visual cue then, e.g. double bass would play before the violins in the front? I guess you can't precisely solve this problem for more than a single listener.

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.

Since light travels a lot faster than sound, I imagine the visual cues of conductor and/or lead of your section and practice of staying on beat matter more than hearing someone across the symphony.

It’s the same for organists in large cathedrals where there is a huge delay and subsequent reverb, as the pipes are often quite far from the player and sound bounces off every conceivable hard surface before making its way back to the organist. They learn to compensate for this mostly by just being very accurate players and trusting that the outcome is correct.