Unfortunately Discord doesn't always cut it. As much as it erks me, many servers use and Require SRS however it's been getting phased out since ED put their own com system in DCS.
I'd prefer to always use in-game vox, but doesn't that restrict you to the historical frequencies used on that AC radio?
So like in the spit you can only listen to one channel at a time and those frequencies are preset and can't be changed in-flight. Not all aircraft on a team might not have the same frequencies. Like if 109's and spits were on the same team, I'm not sure they can comm. I guess SRS doesn't require that restriction and you can monitor multiple channels simultaneously, right? I haven't used SRS in built-in chat much so I might be wrong.
IN game-vox does some interesting stuff with line of sight and blocking radio if your behind a mountain and such or suffer degradation depending on the weather mode in the mission. Or at least they were talking about that. Not sure how many player REALLY want that as opposed to just liking the sound of it (if you'll excuse the pun).